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Agricultural Engineering 



Farm Science Series 



Agricultural Engineering 

By J. B. Davidson, Iowa State College of 
Agriculture and Mechanics Arts 

Field Crops 

By A. D. Wilson, University of Minnesota 
and C. W. Warburton, U. S. Department of 
Agriculture 

Beginnings in Animal Husbandry 

By C. S. Plumb, Ohio State University 

Soils and Soil Fertility 

By A. R. Whitson, University of Wisconsin 
and H. L. Walster, University of Wisconsin 

Popular Fruit Growing 

By S. B. Green, University of Minnesota 

Vegetable Gardening 

By S. B. Green, University of Minnesota 
{OTHER BOOKS IN PREPARATION) 



Agricultural Engineering 

A TEXT BOOK 

FOR 

STUDENTS OF 

SECONDARY SCHOOLS OF AGRICULTURE 

COLLEGES OFFERING A GENERAL 

COURSE IN THE SUBJECT 

AND THE 

GENERAL READER 



BY 



J«4 



ROWNLEE DAVIDSON, B. S., M. E. 

Member American Society of Agricultural Engineers 
Member American Society of Mechanical Engineers 
Member Iowa Engineering Society 

Professor of Agricultural Engineering, Iowa State College 
Joint Author "Farm Machinery and Farm Motors" 



ILLUSTRATED 










■>' 



COPYRIGHT, 1913 
By 

WEBB PUBLISHING COMPANY 

St. Paul, Minn. 

All Rights Reserved 



©CI.A347046 



PREFACE 

Believing that the study of Agricultural Engineering 
should fill an important place in the training of the young 
man who would make farming the object of his life's work, 
the author has attempted to furnish in this volume an aid in 
supplying this part of his training. The application of 
agricultural engineering methods to agriculture should not 
only raise the efficiency of the farm worker but should also 
provide for him a more comfortable and healthful home. 

This volume has been written primarily as a text for 
secondary schools of agriculture, and for colleges where only 
a general course can be offered. Claim is not. made for 
much new material concerning the subjects discussed; but 
rather an attempt has been made to place under one cover 
a general discussion of agricultural engineering subjects 
which hitherto could not be secured except in several vol- 
umes and hence impractical for text-book purposes. 

No attempt has been made to outline the exact method 
for the teaching of the subjects, as this must vary with con- 
ditions. It is desirable that classwork upon the text should 
be supplemented by laboratory work. The nature of the 
laboratory work will depend upon the equipment available. 
It is suggested that the equipments on the nearby farms 
may be used to good advantage. Sample machines to be 
used for study may be secured by co-operation with dealers 
in farm machinery. 

The author will be very glad to receive criticisms and 
suggestions from those using this text, in regard to how it 
may be improved and made more useful. The correction 
of any errors will likewise be appreciated. 



8 PREFACE 

Although written primarily for use as a text book, it is 
hoped that this volume will be of interest to those engaged 
in practical agriculture. 

Many of the illustrations were made from photographs 
secured from the files of the Iowa State College. In addi- 
tion, the trade literature of the following manufacturers 
was drawn upon : 

International Harvester Company of America; John 
Deere Plow Co. of Moline, 111.; Moline Plow Co.; W. & L. 
E. Gurley; Eugene Dietzen Co.; Keuffel and Esser Co.; 
Parlin and Orendorff Co. ; Fairbanks, Morse and Co. ; Hayes 
Pump and Planter Co. ; Hunt, Helm, Ferris & Co. ; J. D. Tower 
and Sons Co. ; Western Wheeled Scraper Co. ; Pattee Plow 
Co.; Avery Company; Emerson-Brantingham Co.; M. 
Rumely Co. ; American Seeding Machine Co. ; Oliver Chilled 
Plow Works; Hart-Parr Co.; Red Jacket Mfg. Co.; A. Y. 
McDonald Mfg. Co. ; Louden Machinery Co. ; Gale Mfg. Co. ; 
Sandwich Mfg. Co.; Aspenwall Mfg. Co.; Wilder-Strong 
Implement Co. ; Port Huron Engine and Thresher Co. ; J. L. 
Owens Co.; Charles A. Stickney Co.; Twin City Separator 
Co.; Cushman Motor Works; F. E. Meyers & Bro.; D. M. 
Sechler Carriage and Implement Co.; Roderick Lean Mfg. 
Co.; Janesville Machine Co.; LaCrosse Plow Co.; The John 
Lanson Mfg. Co.; J. I. Case Plow Works; J. I. Case Thresh- 
ing Machine Co. ; Johnson & Field Mfg. Co. ; Racine Sattley 
Co. ; Kewanee Water Supply Co. ; and others. 

Valuable assistance was secured from Mr. M. F. P. 
Costelloe, Associate Professor of Agricultural Engineering, 
Iowa State College, who read the manuscript for Parts I to 
IV, inclusive. Mr. J. H. Weir, the Editor, did very efficient 
work on the manuscript, which is appreciated. 

Ames, Iowa. J. B. Davidson. 

February, 1913. 



CONTENTS 



Chapter 



I. 
II. 

III. 

IV. 

V. 

VI. 

VII. 

VIII. 



IX. 

X. 

XI. 

XII. 

XIII. 

XIV. 

XV. 

XVI. 

XVII. 



Introduction 

PART I— AGRICULTURAL SURVEYING 

Definitions and Uses of Surveying 

Measuring — -The Use, Care, and Adjustment of 

the Instruments 

Field Methods 

Map Making 

Computing Areas 

The United States Public Land Survey 
Instruments for Leveling; Definitions . 
Leveling Practice 

PART II— DRAINAGE 

Principles of Farm Drainage 
The Preliminary Survey . 
Laying Out the Drainage System 
Leveling and Grading Tile Drains 
Capacity of Tile Drains 

Land Drainage 

Construction of Tile Drains 
Open Ditches ..... 

Drainage Districts 



Page 
13 



16 

18 
24 
28 
34 
38 
42 
49 



56 
64 

67 
73 
78 
86 
96 
103 
108 



XVIII. 

XIX. 
XX. 

XXI. 
XXII. 



PART III— IRRIGATION 

History, Extent, and Purpose of Irrigation . 

Irrigation Culture 

Supplying Water for Irrigation .... 
Applying Water for Irrigation 
Irrigation in Humid Regions and Sewage Dis- 
posal 



Ill 

115 
122 
129 

136 



10 



CONTENTS 



Chapter 

XXIII. 

XXIV. 

XXV. 

XXVI. 

XXVII. 

XXVIII. 



XXIX. 

XXX. 

XXXI. 

XXXII. 

XXXIII. 

XXXIV. 

XXXV. 

XXXVI. 

XXXVII. 

XXXVIII. 

XXXIX. 

XL. 

XLI. 

XLII. 

XLIII. 

XLIV. 

XLV. 

XLVI. 

XLVII. 



XLVIII. 

XLIX. 

L. 

LI. 

LII. 

LIII. 

LIV. 



PART IV— ROADS 

Page 

Importance of Roads ...... 141 

Earth Roads 147 

Sand-Clay and Gravel Roads .... 153 

Stone Roads 160 

Road Machinery 167 

Culverts and Bridges 175 

PART V— FARM MACHINERY 

The Relation of Farm Machinery to Agricul- 
ture .... 180 

Definitions and Principles .... 186 

Materials 195 

The Plow 199 

Harrows, Pulverizers, and Rollers . . 211 

Seeders and Drills 223 

Corn Planters 231 

Cultivators 237 

The Grain Binder or Harvester . . . 244 

Corn Harvesting Machines 251 

Hay-Making Machinery 258 

Machinery for Cutting Ensilage .... 273 

Threshing Machines 278 

Fanning Mills and Grain Graders . . . 282 

Portable Farm Elevators 287 

Manure Spreaders 292 

Feed Mills and Corn Shellers . . . 298 

Spraying Machinery 303 

The Care and Repair of Farm Machinery . 309 

PART VI— FARM MOTORS 

Elementary Principles and Definitions . . 313 
Measurement of Power . . . . . 316 

Transmission of Power ' . 320 

The Horse as a Motor 327 

Eveners 334 

Windmills 339 

The Principles, of the Gasoline Engine . . 344 



CONTENTS 



11 



Chapter Page 

LV. Engine Operation ....... 350 

LVI. Gasoline and Oil Engine Operation . . . 354 

LVII. Selecting a Gasoline or Oil Engine . . 361 

LVIII. The Gas Tractor 370 

LIX. The Steam Boiler 376 

LX. The Steam Engine . . • 385 

LXI. The Steam Tractor 389 

PART VII— FARM STRUCTURES 

LXII. Introduction and Location of Farm Buildings . 395 

LXIII. Mechanics of Materials 402 

LXIV. Mechanics of Materials and Materials of 

Construction 406 

LXV. Hog Houses 414 

LXVI. Poultry Houses 425 

LXVII. Dairy Barns . . . . . . . .436 

LXVIII. Horse Barns 442 

LXIX. Barn Framing 445 

LXX. The Farmhouse 451 

LXXI. Constructing the Farmhouse .... 455 

LXXII. The Silo 461 

LXXIII. The Implement House and Shop . . . 473 

PART VIII— FARM SANITATION 

LXXIV. The Farm Water Supply 480 

LXXV. The Pumping Plant 486 

LXXVI. Distributing and Storing Water . . . .491 

LXXVII. Plumbing for the Country House . «. . 497 

LXXVIII. The Septic Tank for Disposal of Farm Sewage . 501 

LXXIX. The Natural Lighting of Farm Buildings . 506 

LXXX. Lighting the Country Home 510 

LXXXI. The Acetylene Lighting Plant .... 515 

LXXXII. The Electric Lighting Plant 520 

LXXXIII. Heating the Country Home .... 525 

LXXXIV. Ventilation of Farm Buildings .... 531 

PART IX— ROPE WORK 
LXXXV. Ropes, Knots, and Splices 537 



Agricultural Engineering 



INTRODUCTION 

Engineering. Denned briefly, engineering is the art of 
directing the forces of nature to do economically the work 
of man. The pursuit of agriculture requires many mechani- 
cal operations whose execution involves the use of engineer- 
ing methods. 

Consider the production of wheat. The plowing, the 
pulverizing and smoothing of the soil, the cleaning and grad- 
ing of the seed, the drilling of the seed, the harvesting, the 
thrashing, and the hauling of the crop to market, are all 
mechanical operations to which the skill of the mechanic or 
engineer should be applied in order to obtain the best results. 

In like manner if the production of other crops be con- 
sidered, it will be found that there are many operations to be 
performed in connection therewith, which will require the 
directing of the forces of nature or the application of engineer- 
ing principles. 

Agricultural Engineering. In the broadest sense, agri- 
cultural engineering is intended to include all phases and 
branches of engineering directly connected with the great 
industry of agriculture. In America it is only recently that 
the term agricultural engineering has come into general use. 
The term rural engineering is used by some to designate the 
same subject. 

It is only within the last few years that the importance of 
agricultural engineering as a branch of agricultural education 
has been recognized. A knowledge of soils and of the plants 



14 AGRICULTURAL ENGINEERING 

and animals of the farm is essential to those who would make 
good farming the aim of their life's work, and these subjects 
should be carefully studied by the agricultural student. 
But the study of agricultural engineering is quite as impor- 
tant in assuring that efficiency in farm management which 
results in the greatest and most permanent benefits. 

The truth of the foregoing statement is better understood 
when one learns that the producing capacity or earning ability 
of the farm worker is in direct proportion to the amount of 
power he is able to control. There was a time when man 
tilled the soil by his own individual efforts, depending upon 
no other source of power than the strength of his own body. 
Later, one beast per worker was pressed into service to draw 
suitable implements. Still later, two animals were used, and 
development has continued, until at the present time we have 
reached the "age of four-horse farming." In other words, 
the four-horse team is now recognized as the most efficient 
one for field work. 

Man as a motor or producer of power is able to develop 
about one-eighth of one horsepower. When use was made 
of one good horse per worker, man's labor capacity was 
increased eightfold. When four horses became the unit, 
his efficiency was multiplied about 32 times. Just now there 
is a desire to increase still further the amount of power for 
each farm worker, by the use of powerful tractors or engines 
arranged for drawing and operating farm implements. 

The application of power to farm operations, which must 
come mainly through the use of machinery, is only one branch 
of agricultural engineering. Some element of agricultural 
engineering is concerned in nearly every department of 
agricultural endeavor. It serves man in one or both of 
two ways : (1) By making it possible to increase the capacity 
of the worker, as just explained; and (2) by making condi- 



INTRODUCTION 15 

tions more desirable and satisfactory, either by relieving the 
worker of hard labor, or by providing more healthful and 
pleasing surroundings. 

Farm Mechanics. The term Farm Mechanics is not as 
comprehensive in meaning as Agricultural Engineering, yet 
it is often used to designate the same branch of education. 
Mechanics is the science of forces and their actions; whereas 
engineering proper is based upon a knowledge of these forces 
and treats more particularly of the directing of them to 
secure their most advantageous use. 

In this text the subject of agricultural engineering is 
presented under the following heads : 

Agricultural Surveying. 

Drainage. 

Irrigation. 

Roads. 

Farm Machinery. 

Farm Motors. 

Farm Structures. 

Farm Sanitation. 

The importance and relation of these various branches 
to agriculture are discussed in the separate parts of the text 
devoted to each. 

QUESTIONS 

1. Define the term engineering. 

2. Show how engineering methods are involved in crop production. 

3. Define the term agricultural engineering. 

4. Is there any relation between the producing capacity of a farm 
worker and the amount and kind of power used? 

5. Distinguish between "farm mechanics" and "agricultural 
engineering." 

6. Name the principal branches of agricultural engineering. 



PART ONE— SURVEYING 



CHAPTER I 
AGRICULTURAL SURVEYING 

Surveying. The object of agricultural, or land, survey- 
ing, in its generally accepted meaning, is to determine and 
place on record the position, area, and shape of a tract of 
land. The various steps taken to accomplish this end con- 
stitute a survey. In addition to the field work with instru- 
ments for measuring distances, angles, and directions, a 
field record, containing figures, notes, and sketches concern- 
ing the work must be kept; the areas must be computed; and 
usually a map, plat, or profile made showing the tract of land 
surveyed. The art of land surveying includes all of these 
various lines of work. 

Uses of Surveying. Agricultural students can well 
afford to spend some time in the study of land or agricultural 
surveying. The object of the work here presented on sur- 
veying is to enable the student to measure and calculate 
accurately the areas of the various fields of the farm and 
to locate the buildings; to prepare a good map setting 
forth the relative size and position of the fields, buildings; 
and fences, and indicating the drains; and to prepare the 
student for the study of drainage and irrigation. 

It is necessary for the farmer to know the areas of his 
fields in order that he may determine accurately the yields 
of the various crops grown. A survey will enable the farmer 
to so divide his farm into fields as to facilitate a system of 
crop rotation. 



SURVEYING 17 

A good map is a means of recording the location of drains 
and water pipes laid beneath the surface of the ground. It 
will also enable the farmer to direct the work of the farm 
more easily, and to make a study of the most convenient 
arrangement of fields and buildings. This method is used 
by architects and engineers in planning buildings and 
engineering work such as factories and railroads. 

Divisions of Agricultural Surveying. The work of mak- 
ing a survey resolves itself into three stages or operations, 
as follows : 

1. Measuring and recording distances and angles, involv- 
ing the use, care, and adjustment of the instruments used in 
the survey. 

2. Drawing the tract surveyed to a suitable scale, or 
proportion. 

3. Calculating the areas of the tracts surveyed. 

QUESTIONS 

1. What is the object of agricultural surveying? 

2. Define a survey. 

3. To what use can a knowledge of surveying be put by those con- 
nected with agriculture? 

4. In what way will a map be of use to the land-owner? 

5. Describe the three divisions of agricultural surveying. 



CHAPTER II 



MEASURING; USE AND CARE OF INSTRUMENTS 

Instruments for Measuring Distances. Often students 
are led to think that it is impossible to make a survey without 
a very elaborate equipment of expensive instruments, but 
this is not true. An agricultural survey, such as is usually 
required by the farm owner or manager, can be accomplished 
with simple and quite inexpensive instruments. Where the 
boundary of the tract of land is known, a practical survey 
may be made with a surveyor's chain or tape. 

Gunter's, Chain. Much of the land in the United States 
was surveyed originally with the Gunter's chain, which is 
now but little used. This chain is 66 feet 
long, divided into 100 links, each of which, 
including the connecting rings at the ends, 
is 7.92 inches long. The links are made of 
steel or iron wire, and the better chains 
have the open joints soldered or brazed to- 
gether. The reason for making the Gunter's 
chain of the length of 66 feet or 100 links is 
owing to its convenient relation to the stand- 
ard units of length and area in use. The 
chain is 1-80 of a mile, or two rods. A 
square chain is 1-10 of an acre. Thus ten square chains 
make an acre, and this, together with the fact that links 
may be written as a decimal of a chain, greatly facilitates 
computations. To illustrate, 1625 square chains equal 162.5 
acres, and 15 chains and 24 links equal 15.24 chains. 




Fig. 1. The 
Gunter's chain, 
folded. 



SURVEYING 19 

The Gimter's chain has been used on all United States 
land surveys; and in deeds of conveyance and other legal 
documents, when the word chain is used, the Gunter's 
chain of 66 feet is meant. 

Table of Linear Measure. 

12 inches (in. or ") make 1 foot (ft. or ') 

3 feet " . 1 yard (yd.) 

5 l A yards or 16^ feet " 1 rod (rd.) 

320 rods " 1 mile (mi.) 

Equivalent Table 



Mi. Rd. 


Yd. Ft. 


In. 


1 320 


1760 5280 


63360 


1 


5V 2 1VA 


198 




1 3 


36 




1 


12 


Table of Gunter's Chain Measure. 




7.92 inches (in. 


or ") make 1 link 


(li.) 


100 links 


" 1 chain (ch.) 


80 chains 


" 1 mile 


(mi.) 


Equivalent Table 




Mi. Ch. 


Li. 


In. 


1 80 


8000 


63360 


1 


100 


792 




1 


7.92 



Table of Surface Measure. 

141 square inches (sq. in.) make 1 square foot (sq. ft.) 

9 " feet "1 " yard (sq. yd.) 

30M " yards " 1 " rod (sq. rd.) 

160 " rods " 1 acre 

Equivalent Table 



A. 


Sq. rd. 


Sq. yd. 


Sq. ft. 


Sq. in. 


1 


160 


4840 


43560 


6272640 




1 


30^ 


272 14 


39204 






1 


9 

1 


1296 
144 



20 



AGRICULTURAL ENGINEERING 



Surveyor's Measure. 

625 square links (sq. li.) make 1 square rod (sq. rd.) 
16 " rods " 1 " chain (sq. ch.) 

10 " chains " 1 acre 

640 acres " 1 square mile, or one section 



Equivalent 


Table 




Sq. oh. 


Sq. rd. 


Sq. li. 


10 


160 


100,000 


1 


16 


10,000 




1 


625 



Cloth and Metallic Tapes. Tapes made of linen cloth 
are not practical to use in land surveying, even when well 
made and water-proofed. They will stretch when pulled up 
tight, and are difficult to handle in the wind. A cloth 
tape is much improved when small brass wires are woven 
lengthwise into it to check the tendency to stretch. Such 
a tape is said to be a metallic tape. These tapes are made to 
wind into a case of sheet metal or leather, and for this reason 
are very convenient to carry about. 
Steel Tapes. The steel tape is 
now the standard measuring in- 
strument, as it has many advan- 
tages. It does not kink, stretch, or 
wear so as to change its length. 
The steel tape may be obtained in 
lengths varying from 3 feet to 1000 
feet. These tapes may be marked 
or graduated in any form desired. 
The two common methods of 
marking the tape are by either 
etching the surface with acid, or stamping the marks on 
solder placed on the tape at the desired places. A tape 




Fig-. 2. A metallic tape. 
This tape has brass or cop- 
per wires woven into it 
lengthwise. 



SURVEYING 



21 




3. A steel tape wound on a reel. 



100 feet long is usually termed the engineer's tape, and 
either this length or the 50 foot tape is the most convenient. 

The average width of 
the steel tape is 5-16 of 
an inch, and the thick- 
ness about .02 of an inch. 
Short tapes are arranged 
to be carried in metal or 
leather cases, but longer 
tapes are carried either 
on reels or are "thrown" 
into a coil from which they can be unwound without danger 
of kinking. 

Arrows, or Marking Pins. For mark- 
ing points temporarily while measuring with 
a tape or chain, arrows, or marking pins, 
are used. These are made of stout wire, 
pointed at one end, with a large eye or ring 
at the other. In order that the pins may 
be easily found in the grass or leaves, a 
piece of colored cloth should be tied to the 
rings. Eleven pins are required for a com- 
plete set, and are best carried on a ring 
Arrows, with a spring catch. 

Range Poles or Flagstaffs are used to 
locate points in establishing a line. They are rods or poles 
usually 6 to 10 feet 'long, made of wood or iron, pointed 
so as to be easily planted in the ground, and painted red 
and white alternately in foot sections. 

Flagstaffs should be placed directly over the points they 
are to mark, and great care should be used to plant them truly 
vertical. Much skill may be attained by practice in estab- 
lishing lines with flagstaffs, and this skill will be found very 
useful in laying out fields, fences, etc. 




4. 
or pins. 



22 AGRICULTURAL ENGINEERING 

The Care and Use of Chains and Tapes. The chain is 
folded by starting at the middle and folding in the two halves 
at the same time. It is opened by holding the two handles 
in one hand and throwing out the chain with the other. 
The steel tape is wound on a reel or thrown into a coil, the lat- 
ter method requiring some practice and skill to prevent kinks. 
Chains and tapes are used in measuring 
horizontal distances; and for this purpose they 
should be held horizontal, or level, when meas- 
uring, not parallel to the surface of the ground. 
The chain or tape should be pulled taut enough 
to overcome the shortening due to the sag. 
Where distances are to be obtained with great 
accuracy, the chain or tape should be tested 
often over a known fixed distance to determine 
the amount of pull necessary to bring it to 
the true length. Chains in constant use re- 
quire frequent adjustment for wear. 

Each pin should be so placed that its thick- 
ness will not be added to the length of the chain. 
Care should be taken to set the pins vertical. 
When chaining up or down slopes, one end of the 
chain must be held high to make it level, when it 
becomes necessary to transfer a point from the 
elevated end vertically to the ground. This can 
best be done with a plumb-bob and string, and 
a wooden when this is not at hand a pin may be dropped 

range pole. 

from the elevated end of the chain or tape and 
the point where it strikes the ground noted. 

In chaining practice, the man leading is called the head 
chainman, and the other the rear chainman. In beginning 
a measurement, the rear chainman marks the starting point 
with one of the eleven pins in the set, and gives the remain- 



SURVEYING 23 

ing ten to the head chainman, who counts them. The head 
chainman then leads away with the chain or tape toward the 
point to which the distance is to be measured. When the 
rear end of the extended tape is near the starting point, the 
rear chainman calls "chain" or "tape," as signal for the head 
chainman not to go too far. The chain is then stretched full 
length, and the rear chainman lines the front chainman with 
the objective point by motioning with his head or other- 
wise indicating the direction he should move. When the 
head chainman has the chain in line, the rear chainman calls 
"stick," indicating that he has the chain to the pin. The 
head chainman then pulls the chain tight, and sets a pin, 
calling "stuck." The rear chainman pulls the rear pin, 
and both men move ahead and repeat the operation from 
the second pin; and so on. When the head chainman has 
placed his ten pins, he calls "tally," and waits for the rear 
chainman to walk forward to him and give him the ten pins 
he has collected. 

Pacing. The ability to estimate distances accurately by 
pacing is often useful. Skill may be developed by pacing 
known distances until the length of the individual pace is 
determined and can be regulated. 

QUESTIONS 

1. What instruments are needed in making a practical survey of a 
tract of land where the boundaries are known? 

2. Describe the Gunter's chain. 

3. Recite the four tables used in measuring surfaces. 

4. Describe the differences in tapes. 

5. Describe the use of range poles. Of marking pins. 

6. How is the chain cared for? The steel tape? 

7. Describe the process of chaining. 

8. In what way will the ability to estimate distances by pacing 
be useful? 



CHAPTER III 



FIELD METHODS 

Making Chain Surveys. For many practical purposes a 
survey made with the tape or chain alone will be quite 
satisfactory. To make such a survey for area, the land 
is divided into rectangles or triangles, or both. The areas 
of any of these may be easily calculated when the length of 
each side is known. 

Making Notes. In all surveys, all figures, notes, and 

sketches should be sys- 
tematically recorded in a 
suitable book, and these 
go to make what is called 
field notes. From these 
notes the map is later 
made and the areas cal- 
culated. 

The most simple 
method of making field 
notes is to make a free- 
hand sketch of the field 
as nearly correct as the 
eye can determine. All 
corners should be designated by letters and the same 
marked on the sketch, which is used as a guide. All 
distances between corners should be recorded, not only 
in the sketch, but also in suitable columns. The points 
where fences, streams, and roads are crossed in measurement 
should be noted on the sketch. If the tract surveyed is so 
large that the sketch is likely to become confused, the entire 



SURVEY or FIELD 


A BCD WITH TAPE 


AB 
BC 
CO 
DE 
EA 
BE 
SO 


14 
ISO 
BOO 
£50 
ISO 
110 
155 






Head chainman R.Roe 
Rear chainman 1. Do e 

Sept./ igii - J hrs- 
Cloudy and cool 

Used steel tape looft. 

Measured each side 

in turn once 












c 










A 


~~~^^$: \ 












E 










Fig-. 6. A form for field notes. 



SURVEYING 



25 



tract may be sketched on one page, and details of certain 
parts on other pages. 

All field notes should be carefully recorded in a well- 
bound, durable, and convenient field book. The standard 
field book has pages about 4 by 7 inches, ruled in any one of 
the several forms of ruling, and is substantially bound. 
The notes should be neatly made with a hard pencil in order 
that they will not blur with use. In the sketches, the cus- 
tomary symbols employed in map making may be used. 
These will be described later. 

Field Methods. In making a chain survey, it is to be 
remembered that since angles are not measured, more meas- 
urements will be required. Many fields are rectangular, 
and their measurement is correspondingly simple. When 
the angles are not right angles they may be determined by 
measuring three sides of a triangle laid off in the corner, 
making two sides or the legs of the triangle coincide with the 
sides of the field. 

Marking Points in a Survey. In making a survey all the 
important points should be marked for future reference. In 
laying out fields and lots, some permanent mark should 
be set at the corners. If a corner 
post is not used, a stone or a 
block of concrete should be set in 
the ground and a cross chiseled on 
the surface to indicate clearly the 
point. Stakes of durable wood may 
be used to good advantage. The 
exact point may be indicated by driv- 
ing a tack in the top of the stake. A 
stake two inches square is often 

i mi r- i i , i *l.- j.1 Fi %- "'■ Sketch showing 

used, ihe field notes describing the how a line may be laid oft 

i ,. p ,-, • , i i i i at right angles to another 

location ol these points should be at a point a. 




26 AGRICULTURAL ENGINEERING 

complete and clear enough to make it easy for anyone to find 
the corners again at some future time. 

PROBLEMS FOR PRACTICE 

(In order to carry out the following problems it will be necessary 
to be provided with equipment consisting of tapes, pins, and range 
poles.) 

1. With chain and range poles lay off a right angle. 

Note. 3, 4, and 5 feet, or corresponding multiples of these dis- 
tances, are sides of a right angle triangle. Give the theorem of geometry 
upon which this is based. (Fig. .7). 

2. Measure the distance between two points a thousand feet or 
more apart and check with the results obtained by the instructor. 

Random Lme_ 




-500' >< 50O' >k 5(Xf- 

True Line 

Fig. 8. Sketch showing' method of locating points on a desired line 
between two points not visible from each other from a random line. 

3. Let each student pace this or some other known distance and 
determine the length of his pace. 

4. Estimate certain distances by pacing, and then measure accu- 
rately with a steel tape. 

5. Chain over a hill between two points not visible from each 
other. 

Range poles should be set at the points and then the chainmen 
with range poles should take such positions on each side of the hill as 
will enable each to see over the hill and past the other chainman to 
the range pole beyond. The chainmen then range each other in, mak- 
ing several trials. 

6. Chain between two points when the view is obstructed by woods 
or other objects. 

To accomplish this, run a trial or random straight line as near as 
possible to the distant point, leaving fixed points at known distances. 
Upon finding the error at the terminus, correct all other points into 
line a proportionate amount. Then the desired line may be chained. 



SURVEYING 



27 



7. Determine the distance to a visible but inaccessible object. 
Use two similar right-angled triangles. Fig. 9. 

8. Prolong a line beyond an obstacle. 

There are several ways to accomplish this, but the use of similar 
triangles is the only method suggested. 

Let A B be points in the line to be prolonged beyond O, an obstacle. 
Make A B C a right-angled triangle. Prolong A C to F, making C F 
equal A C, and C E equal E F, and B C equal C D. Extend D E to I, 
making DG and G I equal to A C, also 
extend F G to H, making G II equal F G. 
Then H I are points in the extended line 
AB. 




Fig-. 9. Sketch showing 
method of measuring to an 
inaccessible point. 




Sketch showing method of extend- 
f a line beyond an obstacle. 



9. Make a survey of the lot on which the schoolhouse stands, 
locating buildings, etc. 

10. Make a survey of the home farm or a part of it, as assigned by 
the instructor. 

11. Make a survey of a lot or a field having an irregular side, by 
taking offsets at regular or irregular intervals, dividing the field into 
trapezoids. (See method of calculating areas of tracts with irregular 
sides) . 

QUESTIONS 

1 . How is a tract of land divided in making a chain survey? 

2. What care should be taken in making field notes of a survey? 

3. What care should be taken in marking permanent corners? 



CHAPTER IV 
MAP MAKING 

Uses of a Map. When a survey of a farm or other tract 
of land has been made, a map should be drawn to show the 
location of the buildings, fences, lots, roads, and of the trees, 
streams, and other physical features of the land. A map 
enables the mind to grasp the facts in a way not possible 
with the field notes alone. Although not generally practiced, 
a good map of the farm can be used advantageously in 
directing the work of the farm. This map should also serve 
as the means of recording the location of drains and water 
pipes placed beneath the surface of the ground. If the fields 
are numbered and the map placed in the office or dining 
room of the home, it may be used as a basis in planning each 
day's work. The map will set also forth in a very forceful 
way any inconvenience in the arrangement of the buildings 
or fields. 

The Final Map. The final map is made from the data 
recorded in the field book. As has been said, a sketch map 
usually forms a very helpful part of the field notes. The 
final map must be drawn carefully as well as accurately, 
and should be made as durable as possible. 

Drawing Instruments. The equipment for making maps 
may be quite extensive, yet the essential instruments are not 
many in number nor are they expensive. A good outfit 
includes the following: A drawing board of soft wood and 
about 20 by 30 inches in size, a T square, a triangle, a scale 
providing at least 10 and 50 divisions to the inch, a ruling 
or right-line pen, a compass for drawing circles, a bottle of 



SURVEYING 



29 



India ink, and a pen, a pencil, an eraser, thumb tacks, etc. 
A bottle of carmine ink is convenient but not necessary. 
When angles are to be plotted a protractor is quite necessary. 
A good quality of drawing paper should be used, or one 
that will stand reasonably hard usage in folding and handling. 
A good quality of paper is known as bond paper, and a con- 
venient size of sheet is 18 by 24 inches. A drawing made on 
this bond paper may be reproduced by blue printing, a 
process similar to the making of photograph prints from 




Pig'. 11. A set of drawing' instruments, consisting" of a drawing 
board, a T square, a triangular scale, two triangles, a protractor, 
a case of instruments, an irregular curve, paper, ink, tacks, etc. 
This sft is more complete than is required for map making as indi- 
cated in text. 



negatives. The process is rapid, requiring but a few min- 
utes, and the cost of the blue-print paper is but a few cents per 
yard. A better print can be obtained, however, from a 
drawing made on tracing cloth, which is thin and so prepared 
as to make it practically transparent. Where expensive 



30 



AGRICULTURAL ENGINEERING 



maps are to be prepared, one of the heavy, serviceable papers, 
like Whatman's hot-pressed paper, is desirable. 

Making the Map. In making a map, the proper scale 
to use, that is, the ratio between the actual distances in the 
surveyed tract and corresponding ones for the map, must 
first be decided upon. In the case of an average-sized farm, 
100 or 200 feet to the inch is a convenient scale. The larger 
the area or the smaller the maps the greater will be the dis- 
tance represented by one inch on the map. If the scale, 
(meaning the instrument used for measuring) be graduated 
so as to give 50 divisions to the inch, it will be easy to use 

with any of the ratios proposed. 
For instance, suppose the ratio of 
100 feet to the inch be adopted, 
then one division on the scale will 
represent 2 feet ; and if 200 feet be 
adopted as a ratio, then one divi- 
sion will equal 4 feet, etc. 

The handling of the drawing 
instruments mentioned is simple. 
The head of the T square, when 
held by the hand against the 
straight edge of the drawing board, 
will permit the drawing of parallel 
lines. By holding the triangle 
against the blade of the T square, 
all vertical lines may be drawn accurately. The ruling or 
right-line pen is used in drawing straight lines on the final 
map with the India ink. 

The first operation to perform in preparing a map is to 
lay off the boundary of the tract to be mapped. Then the 
location of other features may be added. Angles may be 
plotted in by the use of the protractor, if angles have been 




12. Laying out a tri- 
the length of the three 



SURVEYING 



31 



read. The use of instruments for measuring angles will be 
described later. If measurements have been made to 
determine angles, these angles may be laid out with the aid 
of the compass, setting this instrument with the scale and 
describing circles whose radius is equal to the length of the 
sides of the triangle. The map should first be made with a 
pencil, and then, after every feature has been drawn, should 
be inked in. 

Common Topographical Signs. A topographical map is 
one which gives the general character of the land surface, 




SlngleTrack. 
: -L.. ' -, i ' " 7 if 



Double Track. 



Second ry ■• 
Private or Farm. 



Wire Fence. 
"Rai7*~* _ * _ 



Picket^ ;• 

Unfenced Prop. Line. 



Stream. 



Railways. 



Roads. 



Boundaries 



0000000 
00 000 

ooooooo 

000000 



"-- 



: ' ■ ; -. 






h 


H 






i 


L 


ii 


\: 


1 ^ 




/' 




/a 


* 


7 


« \lfl 



Cultivated Land. Windbreak. 



Contour 



Contour 




& 


<S> 


Q 


Q 


<3 


& 


© 


© 


<3> 


© 


© 


© 


@ 


® 


& 


© 



^ ■> o o & o e> 




Lawn. 



Orchard. DeciduousTrees. Evergreens. 



Fig. 13. Conventional topographical signs. 

showing where there are roads, buildings, forests, swamps, 
etc. To facilitate the making of such maps, it is customary 
to use certain symbols or methods of representing certain 
conditions of the surface. A general use of certain symbols 
to indicate certain things has resulted in their being known 



32 AGRICULTURAL ENGINEERING 

as conventional topographic signs. It is not sufficient, how- 
ever, that these conventional signs alone be used, but should 
be supplemented with notes. 

Lettering. Maps made by professional draftsmen or 
engineers have all notes and titles neatly lettered in. The 
ability to do lettering quickly and neatly is a part of the train- 
ing of the engineer. Letters for titles are often made by the 



abcdefghijklmnopqrstuvvJXyz 


IB 3 456 7 8 9 


A BCDEFGHIJKLMNOPQRS TU V W X Y Z 


Inclined Lettering, for Description. 


abcdefghijkln-inopqrs + uvwxyz 


ABCDEF GHIJKLMN0PQR5TUVWXYZ 


IS345 678 9 


Upright Lettering ,f or Captions. 



Fig. 14. Good styles of free-hand lettering. 

use of instruments, but on most maps the letters must be 
made with a form of the writing pen, the only instruments 
used being the T square and triangle with which the guide 
lines are drawn, to assist in making the letters even and of 
uniform height. While it is not best to attempt to duplicate 
the work of the professional engineer, it is desirable that all 
maps be of as neat appearance as practical; and few things 
add to or detract from the appearance of a map quite so much 
as lettering. The best lettering is that which is simple and 
easily and quickly made. A good alphabet is furnished in 
Fig. 14, and is a form of lettering now in general use. The 
beginner should first pencil the letters on the map; and when 



SURVEYING 



33 



an arrangement of the notes is found which is adapted to the 
map, they should be traced with drawing ink. Although 
not absolutely essential, it is suggested that all maps be 
lettered in the customary way. 



Field No. 1 






Field No-E 


35. A. 






35 A 




Pasture 






15 A 




Field No. 3 




Field No. 4 


35 A 




35 A 


^tf' D 




*aal II Ivn. 





Fig. 15. A farm map. 



QUESTIONS 

1. In what way may a farm map be used? 

2. What is the purpose of a sketch map? 

3. What drawing instruments are necessary for map making? 

4. What kind of paper should be used in making a map? 

5. Describe the making of a map. 

6. What is the use of conventional topographical signs? 



CHAPTER V 
COMPUTING AREAS 

Method of Computing Areas. One of the primary objects 
in making a farm survey is the determination of the areas of 
fields and plats. The computation of areas as here described 
is dependent upon a knowledge of mensuration and geometry. 
The general plan to be followed is to divide the tract into 
simple or primary figures whose areas can be easily calcu- 
lated. These familiar rules of mensuration will now be 
reviewed. 

Rectangles. If a tract of land is rectangular in shape, 
its area is found by multiplying its length by its breadth. 
Triangles. If a piece of ground is in the form of a tri- 
angle, its area may be obtained by either of the following 
rules: (1) If the length of one side, and the perpendicular 
distance from this side to the opposite angle, or the altitude 
of the triangle, are known, the area is one-half the product 
of the known side as the base, times the altitude. (2) If all 
three sides of a triangle are measured, 
then the area may be obtained by 
adding the lengths of the three sides 
and dividing the sum by two; from 
this half sum subtract the length of 
each side in turn; multiply together this half sum and the 
three remainders; the square root of the product equals the 
desired area. Thus, if a, b, and c are three sides of a triangle, 

, a + b + c ,. 
and s = , then 




area = [/ s (s-a) (s-b) (s-c) 



SURVEYING 



35 



Parallelogram. (Fig. 17.) The 
area of a parallelogram, a four-sided 
figure with opposite sides parallel, is 
equal to the product of one of its sides 
and the perpendicular distance be- 
tween it and the opposite parallel side. 

Trapezoid. (Fig. 18.) This is a 
four-sided figure with two sides par- 
allel. The area is equal to the pro- 
duct of one-half the sum of the parallel Fis ' 1S " 
sides by the perpendicular distance between them. 

a+b 



Area 



Xh. 



where a and b are the two parallel sides, and h the perpendicular 
distance between them. 

Trapeziums (Fig. 19) are quadrilateral figures, no two of 
whose sides are parallel. A practical 
way to obtain the area of a field of 
this shape is to measure a diagonal 
dividing the field into two triangles 
whose areas may be calculated. It 
is to be noted that averaging opposite 
sides and taking their product will 
not give the area. 

Area abcd = area ACD+area abc. 

Figures With Many Sides. First 
Method: (Figs. 20 and 21.) A many- 
sided piece of land may be likewise 
divided in triangles and its area ob- 
tained in the way described for tra- 
pezium. The triangles may be formed about one of the 
corners of the figure, or about a point wholly within the 




36 



AGRICULTURAL ENGINEERING 




Fig. 21. 



area. It is to be noted that if a point within is taken as 

the apex of all the angles, it would 
be necessary to measure, either all 
three sides of each separate tri- 
angle, or one side of each as a base, 
and the altitude. 

Second Method: (Figs. 22 and 
23.) The area of a many-sided 
figure may be obtained by dividing 
the field into parallelograms formed 
by dropping a perpendicular from 
each corner to a base line projected either across the field or 

on one side. It is to be 
noted that all parallelo- 
grams which are entirely 
outside of the field are 
negative areas, and their 
sum should be subtracted 
from the sum of those 
having a part of their area inside 
of the field. 

Figures With Irregular 
Sides. First Method: The area 
of a field with an irregular side 
like that formed by a stream 
may be obtained by considering 
the irregular side to be formed 
of short straight lines, and 
measuring offsets, or per- 
pendiculars erected from 
a base line to points in this 
Fl§ ' 24- broken line so as to form 

trapezoids, whose areas are easily found. 






SURVEYING 37 

Second Method: If the 
side of the irregular field 
is not of such a character 
as to be readily divided 
into large trapezoids, then 
the offsets may be taken 
at regular intervals along the base line. 

If d be the regular interval between offsets then the area of the 
trapezoid whose sides are h and h ' is equal to one-half their sum mul- 
tiplied by d, or 

Area ABCD = J/2d (h-\-h') 

PROBLEMS 

1. What is the area in acres of a rectangular field whose length is 
1320 feet and whose width is 347^ feet? 

2. How many acres in a field 80 chains long and 13.25 chains wide? 

3. What is the area in square feet of a triangular piece of ground, if 
the length of one side is 339 feet and the altitude on this side as a base is 
92 feet? 

4. The length of the sides of a tract of land in the form of a tri- 
angle are 220,310, and 343 feet. What is the area in acres? 

5. The four sides of a trapezium are 420, 417, 380 and 375 feet 
taken in order around the field, the diagonal from the corner between 
the 417 and the 380 foot sides to the opposite corner is 528 feet. Find 
the number of acres in the tract. 

6. Find the acre area of a road 66 feet wide and 3960 feet long. 

7. Find the area in square feet of a tract of land with an irregular 
shaped side if offsets taken at the regular interval of 50 feet are 0, 25, 
30, 28 and 50 feet, respectively. 

8. How many rows of corn 3 feet 6 inches apart can be planted in 
a field 20 rods wide? How many hills of corn 3 feet 6 inches apart will 
there be in the field if it be 80 rods long? 

9. How many apple trees 20 feet apart may be planted in a 1-acre 
tract in the form of a square? Try a different arrangement of the trees. 

10. At this point the student should be prepared to take up the 
problem of surveying, mapping, and calculating the area of certain 
tracts of land, as the school house yards, lot, field, or even whole farms 



CHAPTER VI 



THE UNITED STATES PUBLIC LAND SURVEY 

In order to facilitate the survey, location, and designation 
of the lands in the United States, Congress in 1785 adopted 
a system since known as the United States Rectangular 
System of Public Land Surveys. This system has been 
modified from time to time but remains substantially as 
first adopted. The earth's surface is like that of a sphere, 
and it would be expected that in attempting to lay out the 
surface into rectangular areas one would encounter many 
difficulties. Yet these difficulties have been very satis- 
factorily met. 

The squares of this system are bounded on the east and 
west by true meridians of longitude, radiating from the 

north pole, and on the 
north and south by 
chords of parallels inter- 
secting such meridians. 
A principal meridian 
is chosen in each land 
district, and from this 
meridian a base line is 
run east, west, or east 
and west, from what is 
called the initial point. 
Standard parallels are 
run east and west from 
the principal meridian at 
intervals of 24 miles. These standard parallels are often 



T.4N. 
R.4-W. 


T.4N. 
R.3W. 


T.4N. 

R.SW. 


T.4N. 
RJW. 


1 


T.3N. 

R.4 W. 


T.3N. 

RJW 


T.3N. 

R.ew. 


T.JN 
R.IW. 


T.SN. 

RAW. 


T.3N. 

R.JW. 


T.SN. 

R.2W. 


TEN- 
R.I W. 




TIN. 
R.4W. 


TIN. 
RJW. 


T.IN. 

R.ew. 


T.IN. 
R.IW. 


Bas 


•e Line 






Initial Poinl 



26. Showing 
bering 



the division and num- 
of townships. 



SURVEYING 



39 



called correction lines. Guide meridians are run north from 
the base line and from the standard parallels at intervals of 
24 miles. These blocks of land are successively divided 
into townships six miles square and then into sections ap- 
proximately one mile square. 

Townships. The townships lying between two consec- 
utive meridians six miles apart constitute a range, and the 
ranges are numbered from the principal meridian, both east 
and west. The townships in each range are numbered 
both north and south from the base line. Thus if a town- 
ship lies 18 miles west 
of the principal meridian 
and 12 miles north of 
the base line, it is de- 
scribed as Township 
(Twp.) 2 N., Range 3 W. 
Sections. Each town- 
ship is divided into 36 
sections of 1 square mile, 
or 640 acres more or less, 
the exact areas being- 
subject to the conver- 
gence or divergence of Fig. 27 
the meridians, which 
amounts to about a foot for each mile. 

Sections in all of the more recent surveys are numbered, 
beginning with the section in the northeast corner of the 
township as No. 1, and proceeding as indicated in Fig. 27. 

Subdivisions of Sections. Each section may be divided 
into one-fourth section, or 160 acres, or into still smaller 
divisions of 80, 40, or 10 acres. Each of these divisions may 
be described by its location in the section. Thus a quarter 
section of 160 acres may be the N.E.K, S.E.^, S.W.K, or 



s 


5 


4 


J 


2 


1 


7 


3 


9 


IO 


» 


12 


IS 


11 


16 


« 


/■*- 


13 


19 


20 


21 


22 


23 


24- 


30 


29 


28 


£1 


26 


25 


31 


JZ 


JJ 


34- 


Z5 


■36 



The numbering of the 
in the township. 



40 



AGRICULTURAL ENGINEERING 



the N.W.K of Sec— Twp— Range— . An 80-acre tract 

may be the E.y 2 , W.y 2 , S-34 or N.3^ of etc The 40- 

acre and smaller tracts may be described in a similar manner. 

Monuments. In making the original surveys, the gov- 
ernment surveyors left what are called monuments to mark 
the location of principal corners. These monuments were 
usually made of stone with suitable marks to identify them, 
but in some instances only wooden stakes or heaps of earth 
were used. 

Surveys by Metes and Bounds. Before the adoption of 

the rectangular system of 



A/. W % 
160 A 



N.CK, 

NW!x 



40A. 



S.\N.E.k 
80 A 



5e 

T 4 N.R.I VI. 



land surveying, the lands in 
the United States were sur- 
veyed by describing fully the 
boundaries, and it was not 
practical to change to the 
new system where land had 
been so surveyed. This sys- 
tem is still used to a certain 
extent to describe small 
tracts of land even when the 
rectangular system might be 
used. 

Resurveys. It is not the purpose of this text to include 
directions for surveying units larger than the farm, and it 
does not attempt to give directions for a resurvey of the loca- 
tion of the corners of a certain tract, yet some of the impor- 
tant features of such a survey may be mentioned. 

One of the most important considerations is that when the 
boundaries of the public lands established by the authorized 
government surveyor are approved by the surveyor general, 
and accepted by the government, they are unchangeable. 
This is true whether the corners were located where they 



Fig. 28. Divisions of the section. 



SURVEYING 41 

were intended to be or not. Future surveys may be made 
to further subdivide the tract, but as long as the original 
corners are known, no additional surveys can change them. 
If the corners become lost, a resurvey may be made to locate 
them, not where the corners ought to be according to the 
system, but where they were first located. There are many 
considerations and points to be taken into account in the re- 
storation of lost and obliterated corners and subdivisions 
of sections, and it is advised that this be left to the pro- 
fessional and authorized surveyors. 

QUESTIONS 

1. What was the purpose of the United States rectangular system 
of public land survey? 

2. What is the general plan of this survey? 

3. Explain how the land is divided into townships and sections. 

4. How are townships numbered? 

5. How are sections numbered? 

6. Explain how sections are divided and the parts described. 

7. How were comers marked in the original survey? 

8. Describe the process of surveying by metes and bounds. 

9. What is the purpose of a resurvey? 



CHAPTER VII 

INSTRUMENTS FOR LEVELING 

So far our discussion has been confined to instruments 
used for measuring horizontal distances, or those necessary 
to obtain areas. In farm practice, however, it is necessary 
in connection with drainage practice, road construction, etc., 
to determine vertical distances, or the height of one point 
above another even though these points be at some hori- 
zontal distance from each other. 

DEFINITION OF TERMS 

A level surface is one that is perpendicular to a plumb 
line at every point in the surface. It is not a plane nor is it 
a true oblate spheroid, owing to the fact the earth is not a 
homogenous body and the center of mass does not conform 
with the center of form. 

A level line is one that lies wholly within a level surface. 

A leveling instrument is one by which a level plane or a 
level line may be accurately determined. The three appli- 
ances upon which leveling instruments depend are the plumb 
line, a tube filled with liquid, and the bubble tube. 

A datum plane or a datum is the initial plane to which the 
height or elevation of points may be referred. A datum 
plane in common use is that of sea level. 

The elevation of a point is the distance of the point above 
or below the datum plane. 

A leveling rod is a graduated measuring rod or staff 
used for measuring vertical distances between a point on 
which the lower end of the rod may rest and a line indicated 



SURVEYING 



43 



by an instrument. A leveling rod which has a sliding disk 
or target which may be raised or lowered until the center lies 
in the line indicated by the leveling instrument, is called a 
target rod. A rod which may be read from 
a distance or from the leveling instrument 
is a speaking rod. 

Leveling rods are graduated to feet, and 
tenths and hundredths of a foot. In work 
requiring extreme care, the target may be so 
made as to be read to one-thousandths of a foot. 
Bench marks are permanent objects 
whose elevations are known or assumed, 
and which may be used as reference marks 
fcr the elevation of other points. 

The Plumb Line. The plumb line is per- 
haps the simplest and most generally used 
of the leveling instruments. Even the most 
expensive instruments use the 
plumb line to locate the instru- 
ment directly over a given point. 
Provisional levels may be taken 
by means of a combination of the 
plumb line and steel carpenter's 
square, and the difference in 
the elevation of points not far 
apart may be thus obtained. This instrument 
may be used not only in laying drains but 
also in road construction to determine the grade 
of the road and the slope to the side ditches. 
The U Tube or Water Level. This instru- 
ment depends upon the principle that a liquid " seeks its 
level." It consists in two glass tubes fastened vertically 
about three feet apart on a suitable arm and connected with 





Fig. 29. Level- 
ing rods: the one 
on the right is a 
non-speaking rod, 
known as the 
New York; and 
the one on the 
left is a speaking 
rod, known as the 
Philadelphia. 



44 



AGRICULTURAL ENGINEERING 



me of SiGht 
Height of Liquid .s-Bo/ts. 




Corks to be 

Used When 

L e vel is Carried 



a tube. Water is then poured in until it appears at a con- 
venient height in both glass tubes at the same time. The 
surface of the water in each of the two tubes gives two points 

in a level line, which may 

Vr-corks J , CLJ , a be extended to a distant 

leveling rod by sighting- 
over the surface of the 
liquid. 

A water level may be 
made as shown in Fig. 31; 
A and B are short lengths 
of glass tubing attached 
to a board, about three 
feet apart, and connected 
on the lower sides with a 
length of rubber tubing. 
For field use, the board 
is bolted to a staff which 
may be pushed into the 
ground to hold the instrument erect, and corks are provid- 
ed for the upper ends of the tubes to prevent loss of the 
liquid while the instrument is being carried. When leveling, 
these corks should be removed. 

The bubble tube is the basis of nearly all leveling 
instruments. It consists of a round glass tube bent so that 
the upper inside sur- 
face is an arc of a rat^ea^R^^^J^M^^^-^^^- 

circle lengthwise, or 
on a longitudinal sec- 
tion. This tube is 

sealed at each end and nearly filled with ether, the 
remaining space being filled with the vapor of the liquid. 
The upper surface of the tube is usually graduated 



V 



Fig. 31. A home made water level. 




bubble tube. 



SURVEYING 



45 




A carpenter's level 
sights attached. 



with 



or marked to indicate clearly the position of the bubble 
in the tube. 

If the inside of the bubble tube is truly circular length- 
wise, then as the bubble tube is held so as to bring the con- 
vex side of the tube up, it is plain that the bubble will come 
to the highest point. This being the case, a line tangent to 
the curvature of the tube at this point is a level line regard- 
less of the part of the tube in which the bubble may lie. 

If the bubble tube is attached to a frame and placed on 
two supports and one of these supports is raised or lowered 

until, as the frame is 
reversed on the supports, the 
bubble will occupy the same 
position, these supports are 
both in a level line, provid- 
ing the identical points in 
the frame come in contact with the supports in each case. 
Furthermore, the points on the frame will be in a level line 
when the bubble is brought into the position described. 

Thus the carpenter's level, used for leveling buildings, is 
made. If sights are provided on the level, the level line so 
obtained may be extended to a greater distance. A line 
tangent to the bubble tube 
on its inner surface at its 
center as indicated by the 
marks on the tube is known 
as the bubble axis. If the 
bubble tube be revolved 
about a line perpendicular 
to the bubble axis, the bub- 
ble axis will describe a level 
surface. 

The Level. The instrument used generally by engineers 




Fig. 34. An inexpensive farm level 
with horizontal circle for turning off 
angles. 



46 



AGRICULTURAL ENGINEERING 



for determining the difference of elevation between two 
points is known as the level, and involves primarily the ele- 
ments just described, — the bubble axis, a line of sight paral- 
lel to the bubble axis, and a vertical axis perpendicular to the 
bubble axis about which it may be revolved. 

To assist in extending the line of sight, leveling instru- 
ments are provided with telescopes. The sights in this case 
are provided by cross wires or cross hairs, set in the tele- 
scope. 




■J 




Fig. 35. A level known as a Wye Fig. oG. A "dumpy" level, 

level with horizontal circle and com- 
pass. 

THE ADJUSTMENTS OF THE LEVEL 
The Need of Adjustment. Accurate and rapid work 
cannot be done with a level unless it be in proper adjustment. 
Even the best instruments will not remain in adjustment 
indefinitely, and tests of their condition should be made often. 
In practice some of the best engineers make it a rule to test 
their instruments every day. Everyone who uses a level 
should know how to test and adjust it. Its adjustment is not 
a difficult matter, yet it requires some study to master the 
methods used. Every instrument maker of repute will fur- 
nish full and complete directions for adjusting each instru- 
ment of his manufacture, and these directions should be 
given preference over general directions applicable to all 



SURVEYING- 47 

instruments. There is more than one method of making- 
certain adjustments, but only one will be explained here. 

As has been stated, there are three elements in a level 
which should be kept in proper relation: namely, the vertical 
axis, or the line about which the instrument can be rotated ; 
the bubble axis, which is a level line; and the line of sight. 
The last two must be parallel, and the first perpendicular to 
both. If the line of sight be inclined upward, it is obvious 
that all rod readings will be too great, and the error will be 
proportional to the distance of the rod from the level. If the 
line of sight be inclined downward, all readings will be too 
small. If the length of sights, or the distance between the 
level and the stations, be equal in making front and back 
sights, the error in each case will be the same, and the rela- 
tive elevation of the stations will be obtained without error. 
For this reason it is desirable to make fore sight and back 
sight distances equal. 

The adjustment making the vertical axis of the level and 
the bubble axis perpendicular, is a matter of convenience, 
for this will cause the line of sight to describe a plane con- 
taining all the level lines through the instrument. This 
means that it will not be necessary to change or "level up" 
the instrument in sighting in different directions. 

First Adjustment To make the vertical axis of instru- 
ment perpendicular to the bubble axis: 

Adjust the bubble tube to the vertical axis as follows: 
Level up the instrument, bringing the bubble to the center 
of the tube, turn the telescope through 180 degrees, 
and, if the bubble changes position, raise or lower the 
adjustable end of the tube until the bubble is brought half 
way back to its former position. Level the instrument 
again and repeat the operation; and if the bubble moves in 
the tube, make further adjustments. Continue this process 



48 AGRICULTURAL ENGINEERING 

until the bubble does not move in the tube as the telescope 
is turned about the vertical axis. 

Second Adjustment. To make the line of sight parallel 
to the bubble axis: 

Select a level piece of ground for the work, and locate 
three points in a straight line, 100 feet apart. At one end 
point (Sta. A) drive a hub, at the mid-point locate the level 
and take a reading on a rod held on the first hub with the 
instrument carefully leveled. Turn the instrument in the 
opposite direction, and, after leveling carefully, drive a hub 
at the second point (Sta. B) until the same rod reading is 
obtained as at Station A. These two stations now have the 
same elevation, because any error of the instrument will be 
the same in both cases. Now bring the instrument near 
Station A (two or three feet off) and adjust the line of sight 
until the same rod readings are obtained on both stations. 
The rod on Station A may be read by looking through the 
instrument in the reverse way and locating the line of sight 
on the rod with the point of a pencil. After adjusting, the 
operation should be repeated as a check. 

QUESTIONS 

1. Define a level surface. A level line. A leveling instrument. A 
datum plane. 

2. What is meant by the elevation of a point? 

3. Describe a leveling rod. What is the difference between a 
speaking and non-speaking rod? 

4. How are leveling rods graduated? 

5. What is the purpose of a bench mark? 

6. Describe the plumb line. How may it be used to determine a 
level line? 

7. Describe the construction of the water level. 

8. Describe the bubble tube and its use in leveling. 

9. Describe the construction of the engineer's level. 

10. What is meant by the "line of sight"? 

11. Describe the fundamentals of the adjustment of the level. 



CHAPTER VIII 
LEVELING PRACTICE 

Differential Leveling. Differential leveling is the name 
given to the process of finding the difference of elevation of 
two or more points at some distance from each other, with- 
out reference to intermediate points except those required 
temporarily in carrying a line of levels between the points 
whose difference of elevation is required. Differential 
leveling is like profile leveling, except that elevations are 
not taken at regular intervals on the surface. It is desir- 
able, however, to make the sights or the distances between 
the instrument and rod of equal length, as this tends to equal- 
ize errors which may exist in the adjustment of the instru- 
ment. 

Profile Leveling. Profile leveling is for the purpose of 
obtaining the elevations of the surface of the ground. It is 
especially important in this connection, as profile leveling 
is required in the laying out of land drainage systems. 

Leveling. The process of leveling, or in other words the 
performance of the field work in determining the elevation 
of points on the surface of the ground, is comparatively 
simple, yet it is highly important that the work be done 
accurately and that a full record be made of the Work. 

To run a line of levels, a bench mark, or a permanent point 
of reference, should be chosen from which a start is made. 
The importance of the bench mark is all the more magnified 
with an increase in the size of the system of levels. If the 
elevation of the bench mark is not known, it must be assumed. 
For convenience it is usually taken as 10, 20, or 100 feet, 



50 



AGRICULTURAL ENGINEERING 



depending somewhat upon whether the levels are to be taken 
above or below the elevation of the bench mark. 

As for field surveying, a substantial field book should be 
provided for level 
notes. A book of the 
same size as previ- 
ously suggested is de- 
sirable, with ruling as 
showninFig.37. The 
elevationof the bench 
mark is placed in the 
second column oppo- 
site the entry B. M. 
in the first column. 

Set the instrument up half way between the bench mark 
and the first point whose elevation is desired in the line of 
levels. This point is called Station A, and is entered as such 
in the first column of the field book. After the instrument is 



Line of Levels. 




Sta 


B.S. 


HI. 


r.s. 


Elev. 




B.M. 


6.50 


16.50 




10-00 




A 


1.00 


19.40 


4.10 


18.40 




B 


4.05 


21.35 


e.io 


11.30 




C 






3.60 


11.15. 





A form for level notes. 




Fig. 38. Sketch illustrating the levels of Fig. 37. 

brought into a level position, the rodman holds the rod in a 
vertical position over the bench mark, and the levelman takes 
a reading by, over, or through the instrument to the rod. The 
reading thus obtained is the distance of the line of sight 
above the bench mark (B. M.), as the rod is graduated from 
the bottom up and the line of sight is a level line. This 



SURVEYING 51 

reading is called a back sight (B. S.), and if added to the 
elevation of the bench mark will give the elevation of the 
instrument, or the height of instrument (H. I.), as generally 
designated. The first B. S. thus obtained is entered in the 
notes in the second column, opposite the B. M. elevation 
in the first. This B. S. plus the elevation of the B. M. is 
entered in the third column under the head of height of 
instrument, or H. I. 

Thus if the elevation of the B. M. be assumed as 10.00 
feet, and the B. S. reading of the instrument on this point 
be 6.50 feet, the H. I. will be 16.50 feet. 

Now if the instrument be turned so as to extend the line 
of sight in the direction of the first point in the line of levels 
(Sta. A) and a reading be taken in the same way, the reading 
on the rod will be the distance of the elevation of this point 
below the line of sight. The reading is called a fore sight 
(F. S.), and is entered in the fourth column opposite Station 
A., on which the reading was taken. If this fore sight read- 
ing be subtracted from the elevation of the line of sight 
(H. I.), the elevation of Station A will be obtained. For 
instance, suppose the F. S. reading thus obtained is 4.10 
feet, then H. I., 16.50 feet, minus the F. S., 4.10 feet, equals 
12.40 feet, the elevation of Station A, which is entered in the 
proper column opposite Station A. 

To continue the line of levels, the instrument is moved to 
a position midway between Station A, and Station B, 
and, after the instrument is leveled, a B. S. reading is made 
on Station A. This reading added to the elevation of 
Station A gives a new H. I., from which the F. S. reading on 
Station B is subtracted to obtain the elevation of Station B. 

Thus the process is continued until the elevations of all 
the points in the line of levels are obtained. It is easy to see 
how additional readings may be taken with the same height of 



52 



AGRICULTURAL ENGINEERING 



instrument and thus obtain the elevation of several points 
between A and B. This is done in practice. 

It is to be noted in this connection that back sights are 
rod readings on stations or points whose elevations are known, 
and fore sights are readings on stations whose elevations are 
not known. Stations on which back sights are taken are 
generally known as turning points. 

Stakes. It is generally best that all stations be marked 

with a stake driven down close to the ground, on which the 

/.t ,7 ,*« ,2* .'2s- ™ /f ? leveling rod may be placed; 



US- 



as_ 



'22. 



//-? j-/5 



//.*? 



/ 



and turning points should 
always be so marked and 
identified. 

Leveling a Field. It is 
sometimes advisable to obtain 
levels at regular intervals 
over an entire field. This is 
accomplished by laying the 
field off into squares, usually 
by the chain or tape. The 
corners of the squares are 
marked with stakes made of 
lath and the elevation of the 
top of the ground is taken at each corner, as shown in Fig. 39. 
The various corners of the squares are designated by lettering in 
one direction and numbering in the other as shown in the figure. 
Contour Maps. Lines may be drawn over the map of 
the leveled field to indicate points of equal elevation. Such ' 
lines are called contour lines. They offer a very satisfactory 
means of studying the surface of the ground, and a map so 
prepared is especially useful in laying out drainage systems. 
Horizontal Circles for Levels. Many levels are pro- 
vided with horizontal circles or scales, graduated in degrees 



//.f 



/// 

6 



Fig. 39. Plat showing how levels 
may be taken over an entire field. 
The stations are indicated by letter 
and numbers, as B2, etc. 



SURVEYING 53 

and fractions of degrees, which enable the angle between 
lines of sight in different directions to be measured. This 
device is especially useful in laying off right angles, as well as 
in obtaining the angle between two sides of a tract of land, 
and between lines of drains in laying out drainage systems. 

The Compass. A level may be provided with a compass 
box containing a magnetic needle, which will enable the angle 
to be measured between any line of sight and the north and 
south as indicated by the needle. In construction, the mag- 
netic needle is a fine hardened piece of steel carefully balanced 
and hung on a delicate pivot and so arranged as to swing 
within a graduated circle. In order to protect the pivot 
while the instrument is being carried about, a little device 
is provided to lift the needle from the pivot. In most 
localities the needle does not point truly north and south, 
inasmuch as the magnetic pole does not always lie due north ; 
and furthermore, the location of the magnetic pole varies 
from time to time. If the true north is desired, it is neces- 
sary to make the corrections for the location of the magnetic 
pole. This variance from the true north, or meridian, is 
called the declination of the needle. In reading the needle, 
if no correction is made, it is customary to indicate that the 
reading is magnetic (Mag.). 

The Bearing of a Line. The direction of a line is called 
its bearing; in other words, the bearing is the angle that a line 
makes with the direction of the magnetic needle. If the 
direction of a line, beginning with the instrument, lies within 
90 degrees to the right or the left of the needle, it is said to 
have a north bearing, or a northing; and likewise, if it lies 
within 90 degrees of the true south, either east or west, it is 
said to have the south bearing, or a southing. If the line 
lies to the east of north, it is also said to be east, and if to the 
west, it is said to be west, and is so designated following the 



54 



AGRICULTURAL ENGINEERING 



number of degrees indicating the angle of the line with the 
true north or south. Thus, a line in the right-hand quadrant 
is north and so many degrees east; as, N. 4° 37 . E. A line 
whose direction lies in the left-hand quadrant is north, and 
so many degrees west. 



The Transit. 




A surveyor's transit. 



It is not the purpose to include here 
instructions in the use of the 
transit. It is desirable, how- 
ever, to explain in a brief way 

!*» the instrument. The transit is 

a universal surveying instru- 
ment, and it is arranged for 
measuring horizontal and verti- 
cal angles, for determining the 
bearings by the magnetic needle, 
for leveling, for measuring dis- 
tances .by means of an attach- 
ment known as stadia wires, 
and for determining bearings 
from the sun when provided 
with a suitable solar attach- 
ment, and for many other lines 
of work. 
PROBLEMS 



The instructor should here arrange practice work in differential 
and profile leveling, and surveying with the horizontal circle and com- 
pass as far as the equipment provided will permit. 

QUESTIONS 

1. What is meant by differential leveling? 

2. What is the purpose of profile leveling? 

3. Describe the process of leveling. 

4. How should level notes be recorded in the field book? 

5. What is meant by a back sight? Height of instrument? 
Fore sight? 



SURVEYING 55 

6. Describe the process of leveling a field. 

7. What is a contour map? 

8. What is the use of the horizontal circle found on some levels? 

9. Describe the compass. 

10. What is meant by the "declination of the needle?" 

11. What is the "bearing" of a line? 

12. Describe the surveyor's transit, and for what may it be used? 

REFERENCE TEXTS 

The Theory and Practice of Surveying, J. B. Johnson. 
A Manual of Field and Office Methods for the Use of Students in 
Surveying, William D. Pence and Milo S. Ketchum. 
Plane Surveying, John Clayton Tracy. 



PART TWO— DRAINAGE 



CHAPTER IX 
PRINCIPLES OF FARM DRAINAGE 

Regulation of Soil Water. All vegetation is dependent 
upon the water or moisture in the soil for life and growth. 
Water dissolves the plant food in the soil and enables the 
plant to absorb and circulate it throughout its structure. 
Water also being transpired or given out by the plant, has a 
cooling effect, which counteracts the heat of the burning 
sun and prevents the plant from being withered or burned 
up. The amount of water used by plants for their most 
satisfactory growth is called the duty of water. Nature does 
not always supply water to the soil in quantities conducive 
to the most satisfactory growth of the plant. Often there is 
too little water, and many times there is too much. Land 
is drained for the purpose of relieving the soil of the surplus 
water. 

History of Drainage. The practice of land drainage 
runs back to a very early date. Some of the most interest- 
ing drainage projects of early times are the drainage of the 
fens of England and of Haarlem Lake in Holland. Land 
drainage by means of tile was introduced in Europe as early 
as 1620, but it did not come into general use until about 1850. 
Land drainage by tile was begun in the United States as 
early as 1835, by John Johnson, a farmer of Geneva, New 
York. These early drain tiles were made by hand. Tile- 
making machines were introduced about 1848, and from this 
time on, tile drainage increased rapidly. 



DRAINAGE 



57 



The area of the land in the United States which may be 
improved by drainage is still large. It is estimated by Mr. 
C. G. Elliott, formerly Chief of Drainage Investigation, 
United States Department of Agriculture, that there are 
yet 70,000,000 acres of land in the United States to be 
reclaimed by drainage. In addition to this there are large 
areas of land which could be made more productive and more 
valuable by drainage. 

Water in the Soil. The water in the soil may be classified 
as capillary water and hydrostatic water. "Capillary water 




Land needing' drainage. Typical conditions in northern Iowa 
and southern Minnesota. 



is that which covers the surface of the soil particles or grains 
as a film. It is the water in the soil which moves toward the 
surface by capillarity as the water at the surface evaporates. 
Hydrostatic water, or ground water, is that which fills the 
open spaces between the soil particles and which obeys gravity 
to the extent that it may be drawn off at the bottom 



58 



AGRICULTURAL ENGINEERING 



of a layer of soil if a suitable outlet be provided. When 
water exists on soil particles in a very finely divided state it 
is often called hygroscopic water. It is understood that 
capillary water, as defined, would include this hygroscopic 
water or moisture. 

Lands Requiring Drainage. In general, land having an 




Fig. 4 2. A good crop of corn on land which was a swamp the year before. 

excess of water over that required to furnish the best con- 
ditions for plant growth, needs under drainage. The exact 
conditions prevailing when an excess is present may be out- 
lined as follows: 

1. Comparatively flat land in which water collects in 
basins or ponds from the higher surrounding land. 



DRAINAGE 59 

2. Land kept continually wet by water appearing at the 
surface, having seeped or passed underneath the surface 
from land at a higher level. Such a condition is due to the 
action of springs. 

3. Flat land underlaid with an impervious stratum of 
clay which prevents the water from sinking downward 
through the soil. Often this condition is represented by an 
old lake bottom. 

4. Lands on which certain crops are grown, such as rice 
fields or meadow lands, to which irrigation water may be 
applied and removed at will. 

5. Lands subject to overflow by rivers or tides. 

Kinds of Soils. The kind of soil to be drained must by 
all means be considered in connection with the planning of 
farm drainage. The amount of capillary water that the 
soil will hold varies largely with the fineness of the particles ; 
but a very fine soil will not allow water to pass through it 
quickly, and for that reason is designated as a retentive soil. 
There are other factors involved besides the fineness of the 
soil particles; for example, the working or mixing of a finely 
divided soil, such as clay soil, while filled with water tends to 
make it impervious, or water-tight. 

An open soil is one through which the water will pass 
quickly, and in which the pore space is not so finely divided 
as in a retentive soil. The volume of the space between the 
soil particles may be greater in the retentive soil than in the 
open soil, as this space generally increases with the fineness of 
the particles. 

Kinds of Underdrainage. All soils need under drainage, 
that is, the hydrostatic or ground water should be drawn 
off from the soil in some way. In most cases this under- 
drainage is provided by nature, and the ground is said to have 
natural underdrainage. The same may be true where the 



60 



AGRICULTURAL ENGINEERING 



surface of the ground is such as to give good surface drainage, 
as where the land has a good slope. However, where natural 
underdrainage is not provided, or where the surface is such 
as not to provide surface drainage, artificial drainage should 
be installed by means of tile drains or open ditches. 

Underdrains. Artificial underdrainage is generally 
accomplished by providing conduits, as open pipes, which 
will provide a free , and as far as possible, an unobstructed 




Fig. 4 3. An open drain. 

passage for the flow of the water through the soil. To 
secure the best results, these tile lines should have as much 
fall or slope as is practical in order to give a high velocity of 
flow to the water within them, and they should be as straight 
as possible and free from sags and obstructions. 

Open Drains. Open drains or ditches are simply free, 
open channels for the flow of water, where large quantities 
are to be cared for. They are' used where a system of under- 
drainage made of tile would not be practical. The advan- 



DRAINAGE 61 

tages of closed or underdrainage, where it may be used, are 
obvious. It does not interfere with the cultivation of crops 
or other operations conducted on the land. 

Benefits of Drainage. Preparatory to the installation 
of the farm drainage system, must come the consideration of 
the benefits to be derived and an estimate to determine the 
advisability of the expenditure required, from the stand- 
point of an investment. Certain drainage systems may be 
justified as a protection to the health of the people of the 
neighborhood. This value cannot be computed in dollars 
and cents. Yet most farm drainage must be considered from 
the business standpoint. In this connection full considera- 
tion should be given to all of the benefits which may be 
derived from the improvement of the land by drainage. In 
general, it is to be expected that drainage will either reclaim 
the land for farming purposes or make it more productive. 
There are various ways in which land is made more produc- 
tive by drainage. 

Soil is Made Firm. When the level of the hydrostatic 
water is lowered, the soil above becomes more firm. Thus the 
wet marshy field in which a horse would mire may be made 
so firm by drainage as to permit a team and load to pass over 
it safely. 

Soil is Made of Finer Texture. It has been proven con- 
clusively that drainage causes the soil to become divided 
into smaller particles, thus enabling it to hold a larger amount 
of capillary water. The agents which bring about a disin- 
tegration of the soil particles in underdrained soil are the 
percolation, or passing of the water down through it, and the 
action of air and frost. 

The Growing Season Is Lengthened. Drainage lessens 
the amount of water that evaporates from the surface and 
the amount in the soil to be raised in temperature, permitting 



62 AGRICULTURAL ENGINEERING 

the soil to warm up earlier in the spring, and to remain warm 
later in the fall, thus indirectly increasing the length of the 
growing season. The cooling effect of the evaporation of 
water is known to all. 

The Soil Temperature Is Raised. In a manner similar 
to that just explained, the soil is maintained at a warmer 
temperature throughout the growing season, assisting in the 
rapid growth of plants. 

Ventilation. Underdrainage causes the soil to be aerated ; 
for as soon as the hydrostatic water is drawn away by the 
drains, the space between the soil particles is filled with air. 
This has a beneficial effect, since all plants require some air. 

Prevents Surface Wash. When the hydrostatic water 
of the soil is drawn away by underdrainage, the soil is in a 
condition to receive a very heavy rainfall before the water 
will run off over the surface; or, in other words, underdrainage 
will enable the soil to provide a large reservoir for rain water. 

Increases the Depth of Soil. As the soil becomes warmer 
and aerated, the roots strike deeper, thus increasing the 
depth of the soil available for plant food. 

Drouth. Strange as it may seem, well-drained soil 
resists drouth better than wet. The greater fineness and 
depth of the soil enable it to retain a larger amount of capil- 
lary water, which is the water chiefly used by plants. 

The Action of Frost Is Reduced. Soil which is filled with 
hydrostatic water expands upon freezing and is said to 
"heave." Although the action of frost may be beneficial, 
as previously explained, heaving is very injurious to certain 
crops which are planted in the fall. If the ground water of 
the soil is drained out, this action is almost entirely over- 
come. 



DRAINAGE 63 

QUESTIONS 

1. Why is water so necessary to plant life and growth? 

2. What is meant by "duty of water?" 

3. What is the purpose of land drainage? 

4. When was tile drainage introduced in the United States, and by 
whom? 

5. How many acres may be reclaimed by drainage in the United 
States? 

6. Explain what is meant by capillary water. Hydrostatic water. 

7. Give and explain five conditions of land needing drainage. 

8. What is the difference between an open and a retentive soil? 

9. How is artificial underdrainage secured? 

10. When are open drains advisable? 

11. Explain eight primary benefits of drainage. 



CHAPTER X 
THE PRELIMINARY SURVEY 

The Drainage Engineer. The services of a professional 
drainage engineer are well worth their cost. The success of 
any drainage system depends upon whether it is well planned 
or not. If not correctly installed, the whole investment may 
be worthless. Hence a small percentage of this investment 
paid in fees to those who by training and experience know how 
the work should be done is money well spent. It is not the 
purpose of this text to detract from the work of the engineer, 
but rather to lead to an appreciation of his work. 

There is a difference between surveying and engineering. 
Surveying includes only the taking and recording of such 
field observations necessary for the designing of a drainage 
system. The actual work involved in the designing and 
execution may truly be called engineering. This latter work 
involves much skill and experience. 

The Need of a Preliminary Survey. The first step in 
the drainage of any tract of land is the making of a prelimi- 
nary survey or an investigation, which should be for the 
purpose of obtaining a clear idea of the situation and a 
general knowledge of the nature and amount of drainage 
which will be required to accomplish the desired purpose. 

The preliminary survey, then, is the basis upon which the 
next step, involving the actual work of installing the drain- 
age system, must depend. There are many things to be con- 
sidered in the preliminary survey, such as information con- 
cerning the character and value of the land before and after 
improving. Careful investigations should be made to 



DRAINAGE 65 

determine if possible the fertility of the land after improving. 
Then the drainage engineer should go over the tract in order 
that he become thoroughly familiar with it before under- 
taking any instrument work at all. If the tract is large and 
if the ownership is divided, care should be taken that all 
work from the outset shall conform to the law of the state in 
which the tract is located. 

The Extent of the Survey. In the drainage of all but the 
smallest areas it is quite necessary to make the preliminary 
survey before attempting in any way to decide upon the final 
plan. The purpose of the preliminary survey is to obtain the 
data from which the final plans must be made. The data 
secured should include the area of the drainage basin, 
location of the water-shed, direction of the slopes and water 
courses, and should indicate soil conditions and possible 
outlets. 

In securing this data it is necessary that the work be done 
carefully. Mistakes are costly and can only be avoided by 
careful work in securing correct information in the prelim- 
inary survey. Careful work with crude instruments is often 
more satisfactory than hasty work with expensive equip- 
ment. 

Investigation of the Subsoil. An investigation of the 
character of the soil and subsoil should be made a part of the 
preliminary survey, for on the data thus secured will depend, 
to a large extent, the depth of and distance between tile 
lines. This is quite important in land that is underlaid 
with sand and gravel or with an impervious stratum of clay. 
These investigations can best be made with the soil auger. 
This tool can be made by welding a long handle to an ordinary 
V/2 or 2-inch carpenter's auger. See Fig. 53. 

Preliminary Instrument Work. An engineer's level 
should be used in the preliminary survey to obtain elevations 



G6 AGRICULTURAL ENGINEERING 

which will show definitely the lay of the land. It is not safe 
for even the most experienced to estimate slopes by the 
naked eye. 

Map of the Preliminary Survey. A sketch or map 
should be made indicating the location and elevation of the 
low and wet areas in the land, and also the watershed. In 
some cases where the land is quite flat it is desirable to take 
levels at regular intervals over the entire tract, and, perhaps, 
to prepare a contour map as explained in a previous chapter. 
With this information it is possible to lay out the drainage 
system, if conditions show that a practical system is possible. 

It is desired to lay special emphasis upon the importance 
of this preliminary survey. The quite common practice of 
laying tile largely by guess, without a consideration of the 
land area to be drained or the capacity of the tile, cannot be 
too severely criticised. The large amount of insufficient 
and unsatisfactory drainage to be found everywhere is silent 
testimony to the statement that tile drainage must be done 
carefully and intelligently. 

QUESTIONS 

1 . What is the purpose of a preliminary survey? 

2. Why should a drainage engineer be employed on important 
work? 

3. What is the difference between surveying and drainage engineer- 
ing? 

4. What should be included in the preliminary survey? 

5. Why should the subsoil be investigated? 

6. To what extent should an instrument be used in a preliminary 
survey? 

7. What should be included in the map of the preliminary survey? 



CHAPTER XI 
LAYING OUT THE DRAINAGE SYSTEM 

Definitions of Terms. Before beginning a discussion of 
drainage systems it is well that the meaning of some of the 
common terms used in connection therewith be explained. 

The discharge end of the tile line or main is called the 
outlet, and the upper or upstream end is called the head. 
The term lateral is used for the single tile line with no 
branches. The main is the line of large tile that carries the 
discharge from a number of laterals. If the discharges from 
several laterals are received into a larger tile line before it 
reaches the main, the line which receives the discharge from 
the laterals is spoken of as the submain. It is customary to 
designate the laterals and submains by number and the 
mains by letter. 

Direction of Drains. All drains should be placed paral- 
lel to the slope of the surface. The surface of the ground 
water, or the water which flows into tile drains, is usually 
parallel to the surface of the ground, and the water is con- 
stantly flowing down the slope. If a tile line be laid across 
the direction of the slope, it will not receive any water from 
the lower part of the slope; and, in fact, a part of the water 
from above may flow past the tile line. 

Depth of Tile Drains. Except in very retentive soil 
through which the water does not percolate rapidly, the tile 
should be placed at a good depth. It takes little time for 
the water to pass straight down to a tile, but it takes more 
time for it to flow horizontally through the soil. By 



68 AGRICULTURAL ENGINEERING 

placing a tile deep, a large reservoir is provided for rainfall, 
and the tile will have a longer time to carry the surplus away. 
Distances between Drains. It is a practice in some- 
localities where an average soil exists, to consider that tile 
will drain the water from the soil to a distance of one rod for 
each foot in depth. As the ground water flows away through 
the tile lines after heavy rains, the level of the ground water 
is first lowered directly over and near the tile, which causes 
side flow of the water through the soil. If t"he soil is open or 
sandy, this flow through the soil is rapid, and the level of the 



_&- 







<y 






-- /" 



'»■«&= V.; \ it' v ii' 



%% 






Fig'. -14. Sketch showing how the ground water is lowered and the capacity 
of the soil as a reservoir increased by placing the tile deep. 

ground water between the tile lines will be lowered quickly, 
and at no time will it be much higher than the level near the 
tile lines. 

If the soil be retentive and resistant to the flow of the 
water to the tile lines, the ground water may come very near 
the surface at a rod or two from the tile. Thus the distance 
between the lines depends not only upon the depth of the tile, 
but also upon the character of the soil. In practice, lines 
are placed 50, 75, 100, 150, and 200 feet apart, for average 



DRAINAGE 



69 




Natural System 



farm crops, depending upon the conditions and the thorough- 
ness of drainage desired. 

Systems of Tile Lines. There are several general systems 
of arranging tile lines, each 
of which is adapted to cer- 
tain conditions. A descrip- 
tion of the various systems 
follows. 

The natural system con- 
sists in laying tile in natural 
depressions, or it is an at- 
tempt to drain the soil 
needing drainage most. 

The grouping system is 
used where sloughs or basins 
are encountered as well as 
dry land little in need of 
drainage. The grouping system consists of mains running 
into the sloughs with systems of drainage to thoroughly 

cover the area of the soil 
needing drainage. 

The gridiron system is 
used where complete drain- 
age is desired, as on very flat 
fields. The laterals are 
placed parallel, and every 
part of the entire area is 
within a certain distance 
from the tile line. At the 
end of the parallel laterals, 
mains or submains of larger tile are laid to collect the dis- 
charge from as many as possible. 



45. The natural system 
laying out tile drains. 




4C. The grouping system 
laying out tile drains. 



10 



AGRICULTURAL ENGINEERING 




Gridiron System 



4 7. The gridiron system 
laying out tile drains. 



laterals should be avoided 
whenever possible, because 
mains will drain the land for 
some distance on each side, 
and the part of the laterals 
extending across the drained 
area of the main is largely 
useless as far as adding to 
the drained area is con- 
cerned. 

Straight Tile Lines. Tile 
lines should be as straight as 
possible, and when curves 
are required they should not 
be sharp. In addition to the 
fact that the flow of water is 
hindered to a greater extent 
in tile lines with sharp turns 



The single line system is 
one in which the outlet for 
tile lines is an open ditch. 
Tile lines in this case are 
independent of one another, 
and each must have its own 
outlet. 

Large Drainage Systems. 
In laying out a large drainage 
system it may be necessary 
to use several of the various 
methods or systems of ar- 
rangement. There are no 
hard and fast rules for any 
one system, though short 







Single-Line System 

Fig. 48. The single-line system of 
laying out tile drains. 



DRAINAGE 



71 



than in straight tile lines, it is much easier to lay the tile in a 
straight ditch than in a curved or crooked one. The system 
should be so planned that all lands needing drainage should 
be brought under the influence of the drains; or, in other 
words, the system should insure thorough drainage. 

Staking Out the Drains. After the general plan has been 
decided upon, the next step is the staking out of the drains. 
To do this, stations are located at distances of 50 feet apart 
on the line of the proposed drain. Two stakes are required 
at each station. One, the hub or grade stake, is driven into 
the ground, nearly flush 
with the surface, about 
one foot to the left of 
where the center of the 
ditch is to be located, as 
one faces the outlet. 
Levels are taken from the 
top of these grade stakes 
and the cut or depth of 

ditch is figured down from Fig. 49. Grade stakes, or hubs, and 

them. These grade stakes 

may be of any convenient material. Inch boards split into 
widths of about 2 inches are very satisfactory. The length 
should be sufficient to insure that the stake will be solid 
in the ground. Besides the grade stake, guide stakes of 
lath or other light material are required. These are located 
near the grade stakes to aid in finding them, and are 
marked with numbers to identify the stations. 

All stakes should be left in place until the work is finished 
and accepted. They should not be placed long before the 
work is actually to begin, since they are quite likely to be 
moved out of place. 




V&y-rjsfcprade Stake. 
or Hub. 



12 AGRICULTURAL ENGINEERING 

QUESTIONS 

1. What is the discharge end of a tile line called? The upper end? 

2. What is a lateral drain? A submain? A main? 

3. How should tile drains be laid on slopes, and why should they 
be so laid? 

4. How deep should tile drains be placed? 

5. What are some of the factors to be considered in determining 
the distance between drains? 

6. Explain the following systems of tile drains: The natural 
system, the grouping system, the gridiron system, the single line system. 

7. Why should short laterals be avoided? 

8. Why is a straight tile line desired? 

9. What two kinds of stakes are required in staking out a drainage 
system? 

10. Describe the location and purpose of each. 



CHAPTER XII 



LEVELING AND GRADING TILE DRAINS 

Taking Levels. After the drains have been staked, levels 
should be taken with an instrument on the grade stake at 
each station and recorded in the field book. This is the 
process of leveling which has been mentioned in a previous 
chapter. Notes for each line, be it main, submain, or lateral, 
should be kept under an appropriate title or head, and all the 
levels should refer to 
a common datum. If 
the instrument is pro- 
vided with a compass, 
the bearings of the 
line should be record- 
ed on the right hand 
side of the note book 
beside the level notes. 
A good system of 
notes is shown in the 
specimen pages from 
a field book found in 
Part I. 

The Grade. The 
amount of slope given 
to tile drains is called 
the grade and is stated in several ways. The more common 
way is to give the change in elevation of the drain for 
every hundred feet of length. It is also stated as the 
percentage the change of elevation is of the length. Thus 




Taking levels in making - a survey. 



74 



AGRICULTURAL ENGINEERING 



a grade of .02 foot per hundred feet is equal to .02 per cent, 
etc. Again, the grade may be stated in inches per rod, as, 
Yi inch per rod or 1 inch per rod. It is customary to refer 
to the grade as the "fall." Then a grade of .1 foot per 100 
feet is called a "fall" of .1 foot per hundred feet, and a grade 
of 1 inch to the rod has a "fall" of 1 inch to the rod. The 
line of the bottom of the finished ditch, or the line on which 
the tile is laid, is called the grade line. 

Establishing Grade Lines. After the elevations of the 
grade stakes have been obtained, it now falls to the lot of the 

*IOOfh 




Profile of Main. 

Fig. 51. A profile of a tile drain. 



drainage engineer to establish the grade for the tile lines. 
There are two methods in common use for doing this, and 
they will be explained in turn. 

Grade Profile. One simple and also very satisfactory 
way of establishing the grade for the tile drain is to plot 
the system on profile paper, using a vertical scale to show the 
elevations of the various stations, and a horizontal scale, 
the distance between stations. The vertical scale should 
show differences of at least 1-10 of a foot in elevation. It 



DRAINAGE 75 

is now an easy matter to draw trial lines upon this profile, 
locating the grade of the tile drain. The determination of 
the grade line usually resolves itself into the problem of 
locating the outlet as low as possible, with the head deep 
enough to secure good drainage and at the same time high 
enough to provide sufficient fall for the line. 

Sometimes a thread is stretched across the profile as an 
aid in deciding the proper location. After the grade has 
been properly located, the elevation of the grade line at the 
various stations may be read from the scale of the profile. 

Second Method. If the elevation of the grade line at the 
various stations be subtracted from the elevation of the sta- 
tion, the cut, which is the depth of the ditch at that point, 
will be obtained. It is convenient to adjust the grade to 
even hundredths of a foot per 100 feet, as, .02 or .25 foot per 
100 feet. Two additional columns should now be utilized 
in the field book. One should be marked G. L., which is to 
contain the elevations of the grade line at the various sta- 
tions; the other is marked "cuts," and contains the depth 
of the ditch below the top of the grade stakes at the various 
stations. It is possible to locate the grade line and deter- 
mine all cuts at various stations along the line, without the 
extra work in connection with the drawing of the profile, 
but the profile is considered more desirable. 

Uniform Grade Desirable. A uniform grade should be 
used throughout the tile lines as far as possible, though it may 
not be economical in all cases. For example, if the tile line 
is to run through a ridge to an outlet, the grade will likely be 
established by placing the tile at the minimum depth at the 
head end of the tile drain to reduce the cut through the ridge 
as much as possible and still secure a practical grade for the 
tile line from the head end through the ridge. After passing 
through the ridge the grade may be increased. It is always 



76 AGRICULTURAL ENGINEERING 

more desirable to have an increase than a decrease in the 
grade. Where the grade is reduced there is a reduction 
in the velocity of flow at that point, which permits the silt 
in the water to settle in the tile. 

Joining Laterals to Mains. When laterals or submams 
are joined to another drain, it is advisable to have a slight 
fall, or drop, as it is called, into the main at the end of the 
drain. The amount of drop should be proportioned to the 
size of the tile into which the drain discharges. Thus for 
the 6-inch main the drop from the lateral should be 0.2 foot; 
for an 8-inch, 0.3 foot; for a 10-inch, 0.4 foot; and for a 
12-inch, .5 or }/% foot. To compute the elevation of the start- 
ing point for each drain when a drop is to be provided, the 
amount of the drop should be added to the grade elevation 
of the main at the junction. 

Construction Figures. It is customary for the engineers 
having the work in charge to indicate upon the guide stakes 
the cut at the various stations. For convenience of those 
digging ditches, the engineer often changes the decimal of the 
foot to inches. It is also customary to furnish to the tile 
ditcher a tabulated list of the cuts at the various stations. 
Sometimes this is furnished and the marks on the guide 
stakes are omitted. 

The Final Map. After the drainage system has been 
located and all the field observations made, all data should 
be reduced to a permanent map. This map should show the 
location of each drain, its length, head, outlet or junction 
with another line; the number and size of tile required; 
location of all surface inlets, silt basins, etc. It is also well 
to record the grade of the drain from point to point and the 
surface elevations and cuts at representative places. No 
reputable engineer would think of undertaking the design of 



DRAINAGE 



77 



a drainage system without providing the owner of the tract 
drained with such a map. 




A drainage map. 



QUESTIONS 

1. What should be recorded in the field book when taking levels 
for a tile drain? 

2. What is meant by the "grade" or "fall," and in what three 
ways may it be designated? 

3. What is meant by the grade line? 

4. Explain two methods of establishing the grade line. 

5. Why is a uniform grade desirable? 

6. Explain how laterals should be joined to mains or submains. 

7. What construction figures should be placed on the guide stake? 

8. Describe the construction of the final map. 



CHAPTER XIII 
CAPACITY OF TILE DRAINS 

Cause of Flow in Tile Drains. If water be poured into an 
inclined pipe or other conduit, it will flow toward the lower 
end. This flow is produced by the action of gravity. The 
effect of gravity may be observed in the phenomena of falling 
bodies, and the law for the velocity of falling bodies is usual- 
ly expressed by the formula: 



V = 1/ 2 gh 

where V is equal to the velocity in feet per second, g the accelerating 
force of gravity, and h the distance through which the body falls. 

Thus a freely falling body starting from rest will have 
a velocity of 32.2 feet per second at the end of the first 
second. At the end of the second second the velocity will 
have increased to 64.4 feet per second, and there will be an 
increase in velocity each second, or it will continue to accele- 
rate thereafter. It is this same force which causes the flow 
of water in tile drains, and there can be no other agent to 
produce the flow. In the tile drains, however, there are 
many influences to interfere with the acceleration of velocity, 
which tend to make the velocity uniform. 

Velocity Formulas for Flow of Water. There have been 
many attempts to incorporate into a formula the various 
factors which produce and retard the flow in tile drains, and 
many such formulas have been proposed. The extent to 
which these forces retard the flow of water in pipes cannot be 
determined accurately. Some of these forces are the resist- 



DRAINAGE 79 

ance to the entrance of water into the- pipe, the resistance of 
the walls of the pipe to the flow of the water, which varies 
largely with the roughness of the inside of the pipe, the 
obstructions at joints and bends, and the amount of sedi- 
ment deposited, etc. 

Poncelet's Formula. One of the more generally used 
formulas which have been proposed for the flow of water in 
tile drains, is Poncelet's formula. The usual way of stating 
this formula is as follows : 

For mean velocity: 



V = 48 , / dh 

V 1 + bu 

In which 

d = diameter of tile in feet. 

h = head, or difference in elevation between outlet and upper end, 

in feet. 
I = length of drain in feet. 

Modification of Formula. Under varying conditions 
which are encountered, certain modifications of the formula 
will be found necessary. Thus in open soil where the water 
is free to enter the. tile line, it is recommended by Mr. C. G. 
Elliott, formerly Chief of the Drainage Investigations, of the 
United States Department of Agriculture, that 3^ of the 
depth of the soil over the drain at its head be added to the 
quantity dh, making the formula read : 



V " 48 V 1 + 5U 
In which 

k = the depth of the soil over the drain at its head. 

Mr. Elliott also recommends that an increase in the 
head be made in the case of mains which have a com- 
paratively large number of laterals, on account of the drop 
of these laterals into the main. This drop in the submains 



80 AGRICULTURAL ENGINEERING 

tends to increase the velocity of the flow in the mainsi. 
These modifications are not governed by any law and they 
require judgment for their use. 

Run-off from Underdrained Land. In addition to know- 
ing the capacity of a tile drain, the engineer must know 
something about the amount of water which must be taken 
care of from the given area. This is usually spoken of as the 
" run-off, " and is measured by the depth of the water received 
if spread over the entire area. Thus a run-off of Y2 inch for 
an acre is the water received from that area in 24 hours, and 
is sufficient to cover the acre to the depth of ^£ inch. Many 
experiments have been conducted to determine the run-off 
from given areas. Sometimes this quantity is spoken of as 
the "Standard Drainage Coefficient," or "Standard." 
The common standard used for small areas in which tile 
drainage is practiced is the 3^-inch standard. For larger 
areas the standard is larger. In this connection, due con- 
sideration should be made for surface water which may flow 
to the underdrained land from adjoining land. This may 
necessitate the doubling of the capacity of the tile otherwise 
required. 

Application of Formula. In order to use the formula for 

the capacity of the drain tile, it is necessary to know the 

quantity of water discharged per second. This is a simple 

matter, as the quantity of water is equal to the area of the 

drain, times the velocity. Thus, 

Q = av 

where Q is equal to the quantity of water discharged per second, a is 
equal to the area in square feet of the cross section of tile, and v 
equals the velocity in feet per second. 

In addition to this it is necessary to know the number of 
cubic feet per second that is equivalent to the standard used. 



DRAINAGE 



81 



This may be computed by dividing the total quantity of 
water on an acre, for a certain standard or depth, by the 
number of seconds in 24 hours. For convenience, however, 
the following table is included. 



Discharge per second per acre for different depths of run-off. 



Common fraction 


Depth in inches. 
Decimal 


C % i. ft. per sec. 
per acre 


1 

15-16 


1.000 
.938 
.875 
.812 
.750 
.688 
.625 
.562 
.500 
.438 
.375 
.312 
.250 
.188 
.125 
.062 


.0420 
.0394 


7-8 

13-16 


.0367 
.0341 


3-4 

11-16 


.0315 

.0289 


5-8 


.0262 


9-16 


.0230 


1-2 ■... 


.0210 


7-16 


.0184 


3-8 


.0157 


5-16 


.0131 


1-4 


.0105 


3-16 


.0079 


1-8 


.0052 


1-16 


.0026 







In applying the formula it is customary to assume a cer- 
tain size of tile and then make the computation to determine 
whether or not the tile will be sufficient. If too small, 
another trial may be made with a larger tile. As an illus- 
tration, suppose that the size of tile necessary to drain 80 
acres is required, when the line is 1000 feet long and is laid 
to a grade of 4-10 foot per 100 feet, assuming the drainage 
standard or coefficient of }/£ inch. 

Referring to the formula, 
V = 48 



/ dh 
1/ I + 54 d 



82 AGRICULTURAL ENGINEERING 

Assume that an 8-inch tile will be required, then: 

d = diameter of tile, = S inches or % foot. 

1000 

h = total head or fall = .4 X = 4 ft. 

100 

I = 1000 feet. 

ted = 54 X % = 36. 

« = area of cross section of tile = M X 3.1416 X (%) 2 =.349 
square feet. 

V = 48 /j^L± = 48 t/-*_ = 48 V'~0^i 
v 1000 + 36 v 3108 v 

= 2.40 feet per second. 
Q = cubic feet discharged per second, and equals the velocity X 
area of cross section of tile = 2.4 x -349 = .8376. 

Referring to the preceding table for the discharge per 
second per acre for the 34 -inch standard, we find .0105. 
Then the number of acres drained is 

A = = 79.6, or practically 80. 

.0105 

If the answer representing the discharge per second pro- 
cured in this manner should be too great or too small, the 
calculation would be made for smaller or larger sizes of tile, 
as the case may be, and the most practical tile to use chosen. 

To facilitate the use of the formula, a table may be made 
up from it, showing the number of acres which may be drained 
with various sizes of tile laid to various grades. The follow- 
ing is such a table, from Bulletin 68 of the Iowa experiment 
station. 



DRAINAGE 



S3 



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84 AGRICULTURAL ENGINEERING 

Size of Laterals. The size of laterals may be fixed as 
soon as the available fall is obtained by the taking of levels. 
In general, it is not considered good practice to use small tile 
in laterals. The use of 3-inch tile has been quite generally 
discontinued in favor of 4-inch. The larger tile is less apt to 
be influenced by imperfect construction, and the difference 
in cost is small. There is a minimum grade for tile lines 
less than which it is not practical to lay tile. If the soil is 
free from sand or other sediment-forming elements, the grade 
may be quite flat ; however, if the soil is sandy a considerable 
slope should be provided. 

On account of the resistance to flow in small tile, it is not 
best to make lines of small tile longer than a certain length. 
The following table gives the minimum grade and maximum 
length of tile lines which are practical with various sizes of 
tile. 



Table showing minimum grade and length for tiles 


of various sizes.* 


Size of tile in inches 


Minimum grade in 
feet per 100 feet 


Limit of length in 
feet 


3 


.10 
.06 
.06 
.06 
.06 
.05 
.05 
.05 
.04 
.04 


800 


4 


1600 


5 


2000 


6 . 


2500 


7 . 


2800 


8 


3000 


9 


3500 


10 


4000 


11 


4500 


12 


5000 







*From Elliott's "Engineering for Land Drainage.' 



PROBLEMS FOR PRACTICE IN THE USE OF THE FORMULA 

1. Find the number of acres that may be properly drained by a 
6-inch tile line 20 rods long, if laid with a grade of 2-10 of a foot per 100 
feet. 



DRAINAGE 85 

2. What size tile should be used to drain properly a 40-acre tract, 
if the line is 1200 feet long and laid with a grade of 3-10 of a foot per 
100 feet? 

(The following problems are taken from Bulletin 78 of the Iowa 
experiment station, involving the use of the table.) 

3. What size of tile laid to a 0.1 per cent grade will carry the under- 
drainage of 160 acres of flat land? Ans., 15 inches. 

4. What size of tile laid to a 0.2 per cent grade will carry the under- 
drainage of 240 acres, % rolling? Ans., 80 acres flat land plus l /i of 
160 acres rolling gives 133^ acres, requiring a 12-inch tile. 

5. What size of tile laid to 0.3 per cent grade will be required to 
remove both ground and surface water from a pond whose watershed 
includes 40 acres? Ans., 10-in. (Note. — Double or triple the area for 
both ground and surface water.) 

QUESTIONS 

1. What causes the flow of water in tile drains? 

2. What are some of the factors which influence the velocity of the 
flow of water in tile drains? 

3. Give and explain Poncelet's formula. 

4. What modifications of the formula may be made, and why? 

5. What is meant by a standard drainage coefficient, or standard? 

6. How is Poncelet's formula used? 

7. How may the capacity or discharge of a tile be obtained from 
the velocity of flow? 

8. Why is a table convenient in determining the size of tile? 

9. What is meant by maximum length of tile lines? 



CHAPTER XIV 
LAND DRAINAGE 

Digging the Tile Ditch. After the survey and the depths 
of the grade lines at all stations have been marked plainly 
upon the guide stakes, it then becomes the duty of the tiler 
to dig the ditch, or trench, accurately to grade, and to place 
the tile closely and firmly upon the bottom. 




Fig. 53. Hand tools used in digging; tile ditches. Nos. 1 
and 2 are square-end tiling spades, 3 and 4 are open or skele- 
ton tile spades, 5 is a tile scoop or crumber, 6 is a round- 
point shovel, 7 is a tile hook, and 8 a soil auger. 

Hand Digging. Tile ditches are quite generally dug by 
hand, and under certain conditions it is the only practical 
method. The ditch is usually dug so that the center of the 



DRAINAGE 87 

top of the ditch will be about one foot from the line of grade 
stakes. A straight ditch indicates good workmanship. To 
secure straightness, a small rope may be stretched along the 
line of the ditch. Curves may be laid out by using the rope 
as a radius and marking numerous points along the line of 
curve by short stakes. 

The tools required for digging ditches by hand are not 
numerous. A ditching spade with a 16- to 20-inch blade is 
most generally used. In muck soils, an open three-tanged 
spade will be more satisfactory. To clean out the loose soil 
from the bottom of the ditch, a long-handled round-nosed 
shovel is the most efficient tool. To take out the last bit of 
soil and to shave the bottom of the ditch down to an even 
grade to receive the tile, a tiler's scoop, or crumber, is neces- 
sary. 

Ditching Machines. Owing to the large amount of labor 
involved in digging tile ditches by hand, attempts have been 
made for years to design a machine which would do the work 
successfully. At the present time there are some machines 




Fig. 5 1. A tile ditchins' machine at work. 



88" AGRICULTURAL ENGINEERING 

that do very creditable and economical work. Tile ditching 
machines have either a power-driven wheel or an endless 
chain, on which knives and buckets are attached for loosening 
the soil and carrying it above the surface where -it may be 
deposited on a conveyor and carried to one side of the ditch. 
The machine must be so constructed that the cutting 
mechanism can be easily raised or lowered and equipped 
with sights or gauges which indicate clearly the depth the 
machine is digging. Steam and gasoline engines are used 















jr^B 


^^■hv 






" 




*f*r^SF 


_ 




t 








. > v ..'."• ;"-'■''' 



Fig. 55. A large tile ditching machine at work. 



to furnish the power. Traction gearing drives the whole 
machine forward at the proper speed, which, in favorable 
soil, may be as much as 175 feet per hour when digging four 
feet deep or less. 

The great difficulty in the past has .been to design a 
machine which would dig a ditch to grade in soft soil having 
but little supporting power. This has been overcome to a 
great extent by providing caterpillar traction wheels or 



DRAINAGE 



89 



treads which provide a large area of supporting surface. 
These machines can be used to the best advantage on long 
lines of tile and where the soil is reasonably dry and free 
from boulders. In no case should a machine be used which 
does not permit of an inspection of the grade and of the tile 
as it is laid. 

The Guess System of Laying Tile. At the present time 
there is very little tile placed in the ground on grade lines 
made simply by guess. The majority of such systems are 
failures, and mistakes have been so evident where this 
method was practiced that it is uncommon now to see a 
system installed without a survey. 

The Water-Level Method. - But little better than the 
guess method of installing drainage systems, is the water- 
level method, which is used to some extent today and is 
responsible for a large number of failures. This method of 
laying tile is used where there is some water in the ditch. 
Where the fall is slight, water can not be depended upon to 
give a proper grade. The ditch is sure to be dug below the 
grade at certain places, giving a back fall. After the ditch 
has been dug too deep, there is little chance of correcting the 
mistake by filling in. The water-level method is so inaccu- 
rate that, even where 
the fall is great and 
there is little danger 
of creating back fall, 
the grade line will be 
so irregular that the 
efficiency of the tile 
will be much reduced. 

Method of Grad- 
ing- Ditches. Two 
general methods of 




The line method of grading tile 
ditches. 



90 



AGRICULTURAL ENGINEERING 



grading ditches are in vogue. One is to stretch a cord or 
line above the surface parallel to the grade line, using a 
measuring stick to locate the grade. This is generally known 
as the "line and gauge method." The other, the "target 
method," consists in locating a line of sights or targets above 
the ditch, parallel to the required bottom, and the depths at 

all points are gauged by 
sighting over these sights 
and using a measuring 
stick to determine the 
proper depth. 

When the line is used 
it must first be decided 
how far above the bottom 
of the ditch to place it, 
and a measuring rod of 
this length provided. 
Five or seven feet are 
convenient distances for 
the usual depth of dig- 
ging. The line may be 
stretched directly over the 
ditch or to one side. The 
first instance requires that 
a yoke be constructed 
over the ditch, while the 
latter requires only a 
single standard or stake. 
Some tilers object to the line stretched over the ditch, 
as it is more or less in the way, but there is no doubt that 
more accurate measurements can be made when the line is 
so placed. If the line be stretched at one side of the ditch, 
a measuring stick 'with a bracket must be used. To obtain 




The target method of 
tile ditches. 



grading 



DRAINAGE 91 

greater accuracy, a level-tube is sometimes placed on the 
horizontal arm of the bracket. The height of the line above 
the grade stake at each station is obtained by subtracting 
the cut from the distance the line is placed above the grade 
line. Thus, if 7 feet be selected as the length of the measur- 
ing stick, and the cut at a certain station be 3 feet 5 inches, 
then the line should be placed 7 feet less 3 feet 5 inches, 
or 3 feet 7 inches above it. If this operation be performed 
at all stations, it will be seen that the line will be parallel 
to the bottom of the ditch and 7 feet above it. A fishline or 
a fine wire makes an excellent line to use for this purpose, 
as it may be stretched very tight, overcoming the sag to a 
large extent. Some experienced tilers prefer the "target 
method," as it is more convenient. It is, however, more pro- 
ductive of errors. 

Selecting Tile. Great care must be used in selecting 
drain tile. Farm drainage is too expensive for one to take 
serious risks with tile of questionable durability. At the 
present time there is much discussion in regard to the rela- 
tive merits of clay and cement tile. Attention has been 
called repeatedly to instances where both kinds have failed. 
Clay tile has the advantage in that it has been in use a much 
longer time than cement tile, and a good clay tile is as per- 
manent as any material that can be secured. Careful speci- 
fications for tile and methods for testing the same have not 
as yet been prepared or devised. 

Clay tile should be well burned and of uniform shape and 
color. They should be straight, with square ends, and when 
two are held in the hands and struck together they should 
give a good sharp ring. Large lumps of chalk or lime in the 
clay must be guarded against. Inferior tile are those of light 
color, porous and laminated. These are quite sure to become 
disintegrated when placed in the soil. 



92 



AGRICULTURAL ENGINEERING 



Cement tile are very satisfactory when properly made 
and are of recognized quality. No attempt should be made 
to make the tile porous, but as dense a mixture of cement as 
it is possible to secure should be used. Where good coarse 
sand is used, a mixture of 1 part cement to 23^ parts of sand 
has been used by the best manufacturers. A mixture con- 
taining less cement will no doubt make good tile. Large 
cement tile should be reinforced with steel. 




Fig. 5S. Drain tik 



Those at the left are of cement and those at the 
right are clay. 



In installing a drainage system, a careful inspection of the 
tile should be made. All inferior tile which are soft, porous, 
cracked, or overburned until of reduced size, should be 
discarded. 

Laying Tile. Great care should be taken in laying the 
tile. Small tile should be laid with the tile hook (See Fig. 
59), but there is little doubt that the tile is laid more accu- 
rately when laid by hand. Each length should be turned as 
it is laid to secure the best fit. When a tile hook is used on 
tile which are slightly curved, the bend of the tile is quite sure 
to be up, leaving a larger crack at the top of the tile rather 



DRAINAGE 



93 



than at the bottom, which is undesirable. Tile should be 
fitted together so. that 
there are no cracks over 
3^ inch wide. Small holes 
at the joints may be cov- 
ered by broken pieces of 
tile. 

In digging the ditch 
and laying the tile, the 
work should always begin 
at the outlet. The tile 
should be laid as fast as 
the ditch is dug, to pre- 
vent the destruction of 
the ditch by rain. This 
would happen if the water 
should be allowed to flow 
down the unprotected 
ditch. In most soils, the 
open ditches are quite apt 

tO Cave in if left Open F ig. 5 9. Laying- tile with the tile hook. 

during rain storms. 

Laterals should be joined to a main by "Y" connections 

furnished by the tile manufacturers. The cheapness of these 

connections does not justify 
the work of cutting tile to 
form a connection. Laterals 
should enter the main at as 
sharp an angle as convenient. 
When the connection is made 
at right angles, the flow of 
the water from the laterals 

has a tendency to check the flow of the water in the mains. 





Fig-. 60. Sketches showing proper 
method of joining lateral drains to 
mains. From Ohio Exten. Bui. 47. 



94 AGRICULTURAL ENGINEERING 

In laying through quicksand, time should be given for 
the water to drain out and allow the sand to become as firm 
as possible. This is rather a slow process at times, but it is 
the only method to follow in watery quicksand. To prevent 
the sand from flowing into the open end of the tile, a screen 
of hay or grass may be used. If there are bad pockets, it 
may be necessary to lay the tile upon boards to keep them 
to grade. 

Inspection. Before the tile are covered the work should 
be thoroughly inspected to see that the tile are laid to grade, 
and that the openings between the tile are not too large. In 
inspecting the grade, the level may be set over the line of tile 
and the line of sight set to the same slope as the grade line. 
The reading of the rod held upon the top of the tile should be 
the same at all points, so long as the slope of the grade line 
does not change. After inspection, the tile should be 
"blinded in" by cutting enough dirt from the side of the 
ditch to cover it to the depth of two or three inches. This 
earth from the side of the ditch is more porous than that from 
the surface, and permits the water to enter the tile more 
readily. The shoveling and spading of the soil have a ten- 
dency to puddle it and make it water-tight. After blinding, 
the ditch may be filled. 

QUESTIONS 

1. What is the work of the tiler? 

2. Explain in a general way the digging of tile ditches by hand. 

3. Name and describe the tools used in tile ditching. 

4. Where may tile ditching machines be used to advantage? 

5. How much ditch may be dug with a machine in an hour under 
favorable conditions? 

6. Why should not tile be laid by guess? 

7. Explain the "water level" method of installing drains. 

8. Describe the line method of digging ditches to grade. 



DRAINAGE 95 

9. What relation does the line of targets or sights in the target 
method of digging ditches to grade, bear to the grade line? 

10. What points should be observed in selecting drain tile? 

11. Explain in detail how the targets are located. The line. 

12. Describe the use of the tile hook. 

13. How should tile' be fitted? 

14. How may tile be laid through quicksand? 

15. What is meant by "blinding" the tile? 

16. Why should tile lines be inspected? 

17. Describe the work of inspection of tile drains. 



CHAPTER XV 
CONSTRUCTION OF TILE DRAINS 

Filling by Hand. After the tile are laid and blinded in, 
as little hand labor as possible should be used in filling the 
ditches. The usual price for the work of filling ditches by 
hand is ten cents per rod, while the same work will cost one 
to two cents per rod where horses and implements are used. 
Of course there are places near and under fences or embank- 
ments where the ditches must be filled by hand. 




ling' the ditch with a plow. 



Filling with the Plow. One of the most convenient and 
satisfactory methods of filling a tile ditch is to plow it full. 
To do this successfully, an ordinary stirring plow may be 
used, one horse being hitched to each end cf a long double- 



DRAINAGE 



97 



tree which will permit one horse to walk on each side of the 
ditch. The soil and waste banks are plowed toward and 
into the ditch until it is entirely filled. It is best that one 
man drive the team while another hold the plow. Three 
horses may be used upon a twelve-foot evener, two horses 
hitched to one end and one to the other. In this case the 
plow is attached four feet from the end to which the team is 
hitched. The plow is not well adapted for filling ditches dug 
in meadow land. 

Filling with a V Drag. A V drag is a useful and quick 
means of filling ditches. The wings of the drag should be 
vide enough in front to reach from the outside of one bank 
of excavated earth to the outside of the other, and should be 
brought to within a few feet of each other at the rear. 

Filling with Road Machines. A scraping road grader may 
also be used to fill tile ditches. The blade may be set at such 
an angle that the waste bank is scraped over into the ditch. 
Like the road drag, the road machine will do good work if the 
ground is not too wet. 

Another common method is to fill the ditch with a .slip 




Fig. 02. Filling the ditch with a mad grader. 



AGRICULTURAL ENGINEERING 



scraper or other form of handled scraper. A team is hitched 
to the scraper by a chain so as to pull directly across the 
ditch. The scraper is placed behind the waste bank, and the 
team stepping ahead pulls a scraper load of earth into the 
ditch. The team is then backed and the scraper pulled back 
by hand. The latter operation furnishes the greatest objec- 
tion to this system, for it is very heavy work. 

Outlet Protection. All tile outlets should be protected 
in such a manner that the earth will not be washed away 

from the end tile 
and cause them to 
be displaced. The 
cheapest form of 
outlet is made by 
preparing a wooden 
box into which the 
last few lengths of 
tile may be placed. 
This is not a very 
satisfactory form of 
protection. The bet- 
ter plan is to build a 
Fig. 63. a S ood outlet protection for a tile bulkhead of masonry 

drain. It is desirable, however, that grating 

or bars be placed across the outlet to keep out and ail apron UPOn 

small animals. 

which the water 
may spill without washing away the soil. The latter 
may not be needed, or a few stones will generally suffice. 
Concrete makes a splendid bulkhead. A six- to ten-inch 
wall where only two or four feet of earth is to be held 
back will be found sufficient. This wall should extend well 
below the tile to prevent undermining. The last few tile 
should be glazed sewer tile, as they will resist freezing and 
thawing better than common drain tile. Iron rods or netting 




DRAINAGE 



99 



should be placed across the outlet to prevent the entrance of 
small animals which might, by dying in the tile, become an 
obstruction. 

Catch Basins, or Surface Inlets. Where there is sure to 
be considerable surface flow, it is best that this be taken into 
the tile as soon as possible. The catch basin is simply a 
grated inlet leading directly to the tile. The basin is usually 
built deeper than the tile to allow dirt, which might be 
washed in, to settle and not be carried into the tile with the 
water. This sediment should be cleaned out from time to 
time. 

A concrete box, 3^ feet across and with 4-inch walls, 
makes a very satisfactory 



catch basin. The box 
should extend 2 feet below 
the line of tile and should 
have a removable cover. 
Large sewer pipes with 
side connections can be 
used conveniently for this 
purpose. 

Silt Basins. Silt basins 
have been recommended 
for tile lines where the 
grade is reduced, and are 

designed to provide a receptacle to catch the silt that is apt 
to settle at that point. They are constructed with remov- 
able covers through which the sediment may be removed 
from time to time. There is little doubt that these devices 
are very harmful in checking the flow of water in the tile, 
and it has been the experience of the author that these 
basins are never given attention when they require it. 




64. A silt basin. 



100 



AGRICULTURAL ENGINEERING 



Trouble with Roots of Trees. Tile drains laid near 
aquatic, or water-loving, trees, are sometimes partially, if 
not entirely, obstructed by roots of these trees. The willow 
and water elm are among those that give the most trouble in 
this respect. Fruit trees give very little trouble, and drains 
may be laid in orchards with impunity. 

If a drain must pass within 30 or 40 feet of any of the 
trees that are aquatic by nature, the trees should be cut down 




drain which became comp] 
from a willow tri e. 



tclv obstructed by roots 



and killed, or sewer pipes with cemented joints should be 
used near the trees, which will prevent the roots from getting 
into the drains. 

Drainage Wells, or Sinks. Wells are occasionally used 
as outlets for tile drains. It is known that about as much 
water may be discharged into a well as may be pumped from 
it. An investigation of the success of wells as drainage out- 



DRAINAGE 



101 



lets in Iowa reveals that in certain localities wells are emi- 
nently successful; in others, they are failures after a very 
short time. The successful wells seem to be those that 
penetrate crevices in the rock stratum below the surface. 
These wells seem less apt to become clogged with the fine 
silt carried into the well by drainage waters. It is under- 
stood that these wells are to be used for no other purpose 
than as drainage outlets. 

Cost of Drain Tile. To those unfamiliar with tile drain- 
age, it is thought that the following schedule of tile prices 
at the factory will be useful. It is to be remembered that 
prices must necessarily vary with factories, and freight in 
many cases is a considerable item. 



Cost of drain tile at the factory. 



Size of tile in inches 


Weight. Lbs. 


Cost per 1000 


4 

5 


7 
9 
11 
17 
26 
35 


$ 16 
20 


G 


28 


8 


45 


10 


80 


12 


100 



Schedule of Prices for Digging Ditches. The follow- 
ing schedule prices have been in quite general use through- 
out Iowa during the year 1911. 



Cost of digging tile ditches. 



Size of tile 
in inches 


Price per rd. 
3 ft. deep or 

less 


Extra per rd. 

for each inch 

of depth over 

3 ft. 


Extra per rd. 

for each inch 

of depth over 

6 ft. 


4, 5, and 6 

7 and 8 


$.44 
.50 
•62^2 
.75 


$.01 M 

.01 L> 

.02 

.03 


$.03 

.03^ 


9 and 10 


.04 


12 


.05 



102 AGRICULTURAL ENGINEERING 

QUESTIONS 

1. Why is it advisable to use little hand labor in filling the ditches? 

2. How may the plow be used in filling ditches? 

3. Describe the use of the V drag and road grader in filling ditches. 

4. Why should the outlet of a tile drain be protected? 

5. Describe the construction of an outlet protection. 

6. What is the purpose of a catch basin? 

7. Describe the construction of a catch basin. 

8. Where is a silt basin used and what is its purpose? 

9. How may tile drains be protected from the roots of trees? 

10. To what extent may a well be used as an outlet for tile drains? 

11. Compare the prices of drain ti'e furnished in the text with 
those of 3 r our town or city. 

12. What are the usual prices charged for tile ditching? 



CHAPTER XVI 



OPEN DITCHES 

Drainage of Large Areas. Where large areas are to be 
drained, it may not be practical to install tile of sufficient 
size to care for the drainage water or run-off. Thus in the 
large drainage systems it is to be expected that open ditches, 
as distinguished from covered or tile lines, will be used to 
supplement the tile. . 

Construction of Open Ditches. In the construction of 
open ditches, not only 
the size must be con- 
sidered, but also the 
form of the ditch. 
The size of the ditch 
will depend upon the 
capacity of ditches 
dug to various grades 
and upon the area 
and character of the 
catchment basin. The 
capacity of open ditch- 
es will be discussed later. Care should be used in construct- 
ing the banks of the ditch so that the ditch will remain 
open and not become filled by the caving of the banks. 

In certain soils a slope of 1 foot horizontal to 1 foot ver- 
tical for the sides of the ditch may be maintained; and in 
other cases, as in the case of loam soil, the slope must be 1% 
to 1, or even less. In digging a ditch it is often not possible 
to secure the desired slope in the beginning, but the ditch 




A floating dredg 

ditches. 



for digging open 



104 AGRICULTURAL ENGINEERING 

is made deep enough so that as it caves in it will still be of 
sufficient size. The heap of excavated earth from a ditch is 
called the waste bank. The space between the waste bank 
and the edge of the ditch is called the berm. Waste banks 
present an ugly appearance and are an objectionable feature 
of open ditches, unless the earth is used to fill in low places. 

Cost of Open Ditches. Small open ditches are made 
with the plow or scraper. These are usually undesirable, as 
they do not furnish a good outlet for the ground water. 
Large open ditches are generally built by contractors who 
are provided with ditching or dredging machines. In many 
cases these are floating dredges which begin at the head of the 
ditch and dig toward the outlet. There are other types of 
ditching machines, which operate on tracks laid on each side 
of the proposed ditch. These large machines remove the 
earth from the ditch at a very reasonable cost, varying from 
5 to 15 cents per cubic yard. 

Disadvantages of Open Ditches. There are many dis- 
advantages of open ditches. Small ditches do not furnish 
good outlets for the ground water because they cannot be 
kept open to sufficient depth. It is to be noted that an open 
ditch will not drain below the surface of the water in the 
ditch. Again, open ditches interfere seriously with the culti- 
vation of the land, and are very unsightly. They occupy 
so much land as to make their upkeep expensive. Further- 
more, more plant food is carried off by an open ditch than by 
a tile drain. If the water must pass down through the soil 
to a tile drain, more or less of the plant food will be left in 
the soil. 

Capacity of the Open Ditch. As in the case of tile drains, 
there have been many attempts to prepare a formula which 
would enable one to compute the capacity of open ditches. 
There are a good many factors which influence the flow of 



DRAINAGE 



105 



water in ditches. One of the most important of these is the 
cleanness of the ditch. A very little rubbish, if allowed to 
accumulate in an open ditch, will decrease its capacity materi- 
ally. Grass and weeds may grow in an open ditch to such an 
extent as to reduce the capacity of the ditch to less than half. 




Pig. 07. An excavator for digging' open ditches, which is carried on 
tracks laid at each side of the ditch. 

The following tables computed by Kutter's formula will 
be useful in this connection.* These tables are taken from 



*Kutter's formula for the velocity of flow in open ditches is as follows" 



1.811 



+ 41.6.5 + 



.00281 



V = 



1 + Ml. 65 + 



.00281 



X 



1/ 



V 



in which v = velocity of flow in feet per second. 

i = sine of the inclination of the slope, or the fall of the water surface in a 

given distance divided by that distance. _ 
r = area of the cross section in square feet divided by the wet perimeter 

in lineal feet. 
n = coefficient of friction for different sizes of canals and with different 

degrees of roughness. 



106 



AGRICULTURAL ENGINEERING 



Bulletin 78 of the Iowa experiment station. A coefficient of 
roughness of .03 has been used and they are for ditches having 
the sides with slopes of one foot horizontal to one foot vertical . 
The ditches are not to run more than 8-10 full, where the 
capacity is mentioned. Above the upper heavy lines in 
the table the % inch standard of water for 24 hours is used; 
between heavy lines the Yi m ch standard; and below the 
lower heavv lines the M inch standard. 



Number of acres drained by open ditches. 
Depth of water 5 feet. Depth of ditch at least 6J^ feet. 



Grades 






Average width 


of water 






Per 

cent 


Ft. 
per 
mile 


6 

feet 


s 

feet 


10 
feet 


is 

feet 


20 
feet 


30 
feet 


50 
feet 


0.02 


1.0 


980 


1470 


1900 


5000 


7150 


23800 


43800 


0.04 


2.1 


1390 


2090 


2800 


7200 


20400 


33500 


62500 


0.06 
0.08 


3.2 

4.2 


1710 
1980 


2560 
2980 


5100 
6100 


17600 
20400 


24700 
30000 


40800 
48800 


75500 
88000 


0.10 


5.3 


2220 


5010 


7600 


23400 


83400 


54500 


98000 


0.15 


7.8 


2720 


6300 


17100 


28700 


40500 


66700 


120000 


0.20 


10.6 


4820 


7300 


19500 


33000 


47000 


77000 


139000 


0.25 
0.30 
0.40 


13.2 

15.8 
21.1 


5370 
5900 
6830 


16300 
17900 
20600 


21900 
23900 
27700 


37500 
40700 
47000 


53000 
57000 
67000 


86000 
94000 


155000 
170000 


0.50 


26.4 


7600 


23000 


31000 










0.60 
0.70 
0.80 
0.90 


31.7 
37.0 
42.2 
47^5 


16700 
18100 
19000 
20500 


25200 
27300 


33900 











DRAINAGE 107 

Number of acres drained by open ditches. 

Depth of water 7 feet. Depth of ditch at least 9 feet. 



Grade 






Average width of w 


ater 




Per 


Feet 


s 


10 


15 


so 


SO 


50 


cent 


per mile 


feet 


feet 


feet 


feet 


feet 


feet 


0.02 


1.0 


2300 


4700 


16600 


28000 


48000 


88500 


0.04 


2.1 


4850 


6740 


23400 


35400 


58000 


106000 


0.06 


3.2 


5920 


17000 


29600 


43400 


72000 


129000 


0.08 


4.2 


6940 


19100 


34200 


50000 


83000 


150000 


0.10 


5.3 


7720 


21800 


38400 


56000 


92600 


167000 


0.15 


7.8 


19400 


27000 


47200 


68500 


112000 


202000 


0.20 


10.6 


22400 


31300 


54200 


78700 


130000 


235000 


0.25 


13.2 


25000 


34800 


60500 


88000 


146000 




0.30 


15.8 


27400 


38200 


66200 


96500 






0.40 


21.1 


31700 


44100 










0.50 


26.4 


35400 













QUESTIONS 

1. When may it be necessary to use open ditches as drains? 

2. What are some of the disadvantages of open ditches or drains? 

3. What slope is usually given the sides of open ditches? 

4. What is the "waste bank"? The "berm"? 

5. How much does the digging of open ditches cost per cubic yard? 

6. What factors influence the capacity of open ditches? 

7. What formula is generally used in computing the capacity of 
open ditches? 



CHAPTER XVII 
DRAINAGE DISTRICTS 

Definitions. The drainage district is an organization of 
the owners of land for the purpose of constructing and main- 
taining a "drainage system where the cost is to be shared in 
proportion to the benefits derived. Such an organization is 
necessary where an individual cannot drain without involving 
the use of the land of his neighbors. A drainage district 
may include at least three classes of land : First, all of the 
adjacent land which in itself may not be in immediate need 
of drainage; second, land in partial need of drainage; and 
third, worthless land which would be reclaimed by drainage. 

In every drainage district there are two kinds of work: 
First the co-operative work, such as the construction of large 
drains or ditches; second, the individual work required by 
land owners in supplying laterals or submains. 

Drainage Laws. The organization of drainage districts 
is a matter which involves many details and which is subject 
to special laws in most states. These special drainage laws 
usually cover the essential steps of procedure; and the 
features of the organization of a drainage district are as 
follows: First, the right of the property owners to petition 
for the construction of drains alleged to be of public benefit. 
Second, provision for making and collecting assessments, as 
well as the appraisement and payment of damages. Third, 
the establishment of the perpetual right of land owners to 
the use of the drains wnich are to be constructed in the 
district. Fourth, the authority to obtain money by incur- 
ring debt or selling bonds, under the proper legal regulations. 



DRAINAGE 109 

Survey and Report. After a petition has been made for 
the formation of a drainage district, the law places the matter 
of a survey and report of the district in the hands of a board 
or an officer of the law to order the survey and report by an 
engineer. This report should be comprehensive in extent, 
and should furnish sufficient data concerning the district to 
enable the board or the officer of the law to determine whether 
or not it will be of benefit to the district as a whole. 

The report in this case should include an estimate of the 
cost of the work to be performed in the district, covering the 
actual cost of the construction of the drains and the neces- 
sary work in connection therewith, such as construction of 
bridges, etc. It should include an estimate of damages to 
all property owners which may be incurred from the con- 
struction of the drains; also estimates of the cost of the 
engineering, of fees of the commissioners, and of all legal 
expenses arising from the suits which may be carried to court. 

Damages. Provision is usually made for a commission 
of disinterested men to appraise the damages which may come 
to the individual property owners through the construction 
of the drainage work. Sometimes this board of commis- 
sioners is also called upon to levy the assessment of benefits. 

Assessment of Benefits. It is usually provided by law 
that the total cost of the drainage district shall be assessed 
according to the benefits derived. These benefits may be 
either specific or general; specific in that the value of the land 
may be increased, and general in that the health of the com- 
munity is improved by the drainage district. 

There are many things involved in levying an assessment, 
and these are more or less subject to state laws. Copies of 
drainage laws may be obtained by applying to the secretary 
of state in any state, and these laws may be made the subject 
of an interesting study- 



110 AGRICULTURAL ENGINEERING 

QUESTIONS 

1. What is a drainage district? 

2. When is a drainage district necessary? 

3. What three classes of land may it include? 

4. What two kinds of drainage work does it include? 

5. What are the four essential features of laws relating to drainage 
districts? 

G. What is required in the survey and report of a drainage district? 

7. What docs the cost of a drainage district include? 

8. Describe the assessment of damages in a drainage district. 

9. What is meant by assessment of benefits? 

REFERENCE TEXTS 

Engineering for Land Drainage, by C. G. Elliott. 
Practical Farm Drainage, by C. G. Elliott. 
Land Drainage, by Manley Miles. 
Irrigation and Drainage, by F. H. King. 
Notes on Drainage, by E. R. Jones. 
Bulletins of U. S. Department of Agriculture. 
Bulletins of state experiment stations. 



PART THREE— IRRIGATION 



CHAPTER XVIII 
HISTORY, EXTENT, AND PURPOSE OF IRRIGATION 

Control of Soil Moisture. Attention has been called to 
the importance of having the soil contain the proper amount 
of moisture to furnish the best conditions for the growth of 
crops. Plants require that the soil contain a sufficient amount 
of moisture, not only to dissolve the plant food, but also to 
enable them to absorb and assimilate it. Much of the plant 
food in the soil is made available through the action of micro- 
scopic organisms. The vitality of these organisms depends 
largely upon an adequate supply of moisture. As has been 
explained, drainage is for the purpose of relieving the soil of 
a surplus moisture; on the other hand there may be in certain 
localities at times and in other localities at all times a defi- 
ciency of moisture from natural sources. Irrigation is simply 
a process of supplying water to the soil by artificial means, 
either to make it possible to grow crops or to increase pro- 
duction. 

Irrigation, then, is the reverse of drainage; and although 
this be true, it is to be noted that irrigation practice has 
many features in common with drainage. The management 
of water is much the same, regardless of whether it is to be 
removed from the soil as in the case of drainage, or supplied 
to the soil as in the case of irrigation. 

The importance of irrigation may be made clear by calling 
attention to the fact that many crops, like potatoes and corn, 



112 AGRICULTURAL ENGINEERING 

during the part of the growing season when the tubers or 
ears are forming, require a large amount of plant food and 
moisture. At this time the plants have a wonderful root 
development, absorbing a great amount of soil moisture; and 
if maximum yields are to be secured, sufficient moisture must 
be supplied. 

History of Irrigation. The practice of irrigation runs 
back even before the time history began to be written. 
There is evidence that irrigation was practiced along the 
Nile and the Euphrates rivers more than 2000 years b. c. 
There were also large irrigation works in Baluchistan and 
India before the Christian era. Many of these ancient works 
have been abandoned, yet not a few have been maintained 
and are still in use. In the Western Hemisphere, irrigation 
was practiced at a very early date in Peru, in South America, 
and by the Aztec civilization in North America. The 
remains of ancient irrigation works are to be found in parts 
of Arizona and New Mexico. 

Settlers in the vicinity of San Antonio, Texas, began to 
practice irrigation as early as 1715. When the Mormons 
settled in the Salt Lake Valley in 1847, they soon began to 
give attention to the matter of irrigation, and much credit 
for the development of irrigation methods should be given 
to these pioneers. As early as 1870, a colony known as the 
Greely Union Colony was established in northern Colorado, 
and began the construction of works for irrigation. Since 
that time irrigation has grown by bounds in the United 
States. 

Dr. Elwood Meade, former Chief of Irrigation Investiga- 
tions, U. S. Department of Agriculture, has estimated that 
the area now under irrigation in countries from which it is 
possible to secure reliable statistics, aggregates 85,000,000 
acres. Taking into account countries which do not have 



IRRIGATION 113 

statistics, he estimates that the total irrigated area is not far 
from 100,000,000 acres, or about the area of the state of 
California. This area is being rapidly increased. 

Professor F. H. King states in his book, "Irrigation and 
Drainage," published in 1907, that the area irrigated in 
India was about 25,000,000 acres, in Egypt about 6,000,000 
acres, in Italy 3,700,000 acres, in Spain 500,000 acres, and 
in France 400,000 acres. 

The following data are taken from the preliminary report 
of the United States Census of 1910. These figures are for 
the arid states of the United States, and do not include rice 
irrigation. 

Total acreage irrigated in 1909 13,739,499 acres 

Area irrigation enterprises were capable of irrigating 

in 1910 19,355,711 " 

Area included in irrigation projects 31,112,110 " 

Total cost of irrigation systems constructed $304,699,450 

Average cost per acre (based upon construction to July 1, 
1910, and acreage enterprises were capable of supply- 
ing in 1910) $15.76 

Average annual cost per acre of maintenance and opera- 
tion $1.07 

PURPOSES OF IRRIGATION 

To Supply Moisture. By far the most important pur- 
pose of irrigation is to supply moisture when needed for plant 
growth, as has already been explained. In some localities 
crops cannot be grown at all without irrigation, and in others 
irrigation is practiced in order to supplement rainfall and 
increase the crop. 

To Control Temperature. In some localities irrigation is 
practiced chiefly to control the temperature. Cranberry 
marshes are often flooded with water to protect the crop from 
frost. In other localities the soil is warmed in winter by 



114 AGRICULTURAL ENGINEERING 

causing a thin sheet of water to flow over it, and the same 
process may have a cooling effect in summer. This kind of 
irrigation is practiced in Italy where a supply of warm water 
is obtainable. 

To Kill Weeds. In rice fields the surface of the ground 
is flooded in some instances largely for the purpose of killing 
weeds, thus reducing the labor of cultivation. Such a 
system also protects the crop from the ravages of birds and 
insects. 

To Supply Fertility. Irrigation may be practiced in some 
localities in order to supply additional fertility to the soil. 
Some irrigation water carries a large amount of sediment 
which is very rich in plant food. The water may also con- 
tain soluble plant food, as phosphoric acid, potash, and 
nitrogen. The fertility of the land along the Nile, in Egypt, 
which has been irrigated for ages, is maintained largely by 
the addition of fertility through the irrigation waters. 

It is true that some water supplies cannot be used for 
irrigation because they contain poisons injurious to plants. 
This is often true of the water of rivers into which the refuse 
from smelters and certain kinds of factories is discharged. 

Disposal of Sewage. In many instances the disposal 
of sewage waters from cities has not only been facilitated, 
but also made a matter of profit, through irrigation. Sewage 
water, when applied to the soil is quickly purified and made 
harmless. Sewage water is usually very rich in plant food. 

QUESTIONS 

1. Define irrigation. 

2. Why is an adequate supply of moisture in the soil important? 

3. How long has irrigation been practiced? 

4. How much land in the world is now irrigated? In U. S.? 

5. What is the main purpose of irrigation? 

6. Name and describe four other purposes of irrigation. 



CHAPTER XIX 
IRRIGATION CULTURE 

The Amount of Water Required for Crops. As explained 
in the part of the text devoted to drainage, nature does not 
in all cases supply the amount of water which will produce the 
maximum growth of plants. In this connection the question 
of the amount of water which, when properly applied, will 
produce a paying yield of crops, is one of vast importance 
to those interested in irrigation. In most instances irriga- 
tion water is expensive, and for the sake of economy no more 
water should be used than necessary. The question, how- 
ever, is very complex, and cannot be treated otherwise than 
very briefly in this text. 

The water which comes to the soil leaves it in three dif- 
ferent ways: First, a portion of it is transpired through 
plants; second, a portion evaporates from the surface of the 
soil ; third, a certain amount of the water flows away over the 
surface or as underground drainage. Plants grow by using 
water, as described under the first head. The other two 
ways in which the water leaves the soil may be considered 
losses, and should be reduced to the minimum. 

There are many conditions which modify the amount of 
water required for irrigation. These may be enumerated as 
follows. 

The Nature of the Crop Grown. Some crops transpire 
more than others, because they have more foliage to give 
off the moisture. The root growth of the plant is a factor in 
determining the amount of moisture used, as the roots of some 



116 AGRICULTURAL ENGINEERING 

plants strike deep and are thus able to draw moisture from 
a larger volume of the soil. 

Character of the Soil. The amount of water required is 
dependent largely upon the character of the soil; thus the 
soil may be so open or porous as to permit a rather large loss 
of moisture by seepage. The character of the soil influences 
to a rather large extent the effectiveness of the soil mulch 
which conserves the moisture in the soil, which is to be 
described later. 

Character of the Subsoil. The character of the subsoil 
is a factor in determining the amount of water required by 
the plant, for an open subsoil will be the means of a great loss 
of moisture by percolation downward. 

Effect of Cultivation. Cultivation for maintaining a soil 
mulch will influence to a large extent the amount of moisture 
required for most satisfactory plant growth. In dry-farming 
localities, as well as elsewhere, moisture is conserved by keep- 
ing a dust mulch or fine layer of soil over the surface. Much 
of the moisture in the soil available for the growth of plants 
may be retained in this way from one wet season through a 
dry season. After a rain or an application of irrigating water, 
it is customary to cultivate the soil as soon as practical in 
order to form this mulch. 

Closeness of Planting. A dense, heavy crop that shades 
the ground will check the loss of moisture by evaporation, 
thus it is customary to irrigate grain crops most thoroughly 
at the time when they are heavy enough to shade the ground. 

Character of Rainfall. The character of the rainfall is an 
important factor in fixing the duty of water; one heavy rain 
which penetrates the soil to a considerable depth is more use- 
ful than several light rains which are quickly evaporated. 
Thus localities which have a wet season are often able to 



IRRIGATION 



117 



grow crops, even though the actual rainfall is quite small, 
inasmuch as it may be stored in the soil and conserved by 
cultivation for use during the dry season. 

Frequency of Applying Water. In like manner the fre- 
quency of applying irrigation water is a factor which deter- 
mines the duty of water. One good thorough irrigation, 
under most conditions, is preferable to several light appli- 
cations. 

The Amount of Water Used in Irrigation. It is to be 
expected that the student is anxious to know how much 
water must be applied to the soil to supply the plants where 
the rainfall is not sufficient, or where the rainfall is too slight 
to be considered. The amount of water is usually designated 
in inches or feet. This means that the water applied is 
sufficient to cover the entire surface to a depth indicated in 
inches or feet as occasion may require. The actual amount 
of water varies largely, as may be expected. 

Mr. H. M.Wilson, in "Manual of Irrigation Engineering," 
gives the following table setting forth the amount of water 
used in irrigation in different countries. 



Amounts of water used in irrigation in various countries. 



Name of country 


No. of acres per 
second foot * 


Xo. of inches per 
10 days 


Northern India 

Italy 

Colorado 

Utah 


60 to 150 

65 to 70 

80 to 120 

60 to 120 

80 to 100 

70 to 90' 

60 to 80 

60 to 80 

100 to 150 

100 to 150 

150 to 300 


3.967 to 1.5S7 
3.661 to 3.4 
2.975 to 1.983 
3.967 to 1.983 


Montana 


2.975 to 2.38 


Wyoming 

Idaho 

New Mexico 


3.4 to 2.644 
3.967 to 2.975 
3.967 to 2.975 


Southern Arizona 


2.38 to 1.587 


San Joaquin Valley". 

Southern California . . 


2.38 to 1.587 
1.587 to .793 



*See Chapter XXI for definition of this unit. 



118 



AGRICULTURAL ENGINEERING 



Dr. Elwood Meade furnishes the following table as the 
duty of water for different crops in the United States : 

Depth of -water used for different crops and the irrigation season for each. 



Crop 


Depth of Irrigation. 
Feet 


Irrigating season 


Potatoes 

Alfalfa 

Orchard 

Wheat 


3.94 

3.39 
2.76 
2.68 
2.15 
1.73 
1.49 
1.40 


May 17, to Sept. 15 
April 1, to Sept. 22 
April 15, to Sept. 2 
April 1, to July 26 


Sugar beets 

Oats 

Barley 

Corn 


July 13, to Aug. 17 
May 22, to Aug. 20 
June 12, to Aug. 1 
July 24, to July 29 



Crops Grown by Irrigation. Most farm crops can be 
grown successfully by irrigation methods, and no attempt 
will be made here to discuss all. It is desirable, however, 
to discuss some of the chief crops grown in this way. 

Grain. One of the principal crops grown by irrigation is 
grain, and it is one which adapts itself well to irrigation 
methods. When land is brought under irrigation, grain is 
usually one of the first crops to be grown. There are several 
reasons for this. They are food crops and are always in 
demand. They do especially well on virgin soil and they 
require the least output in preparing the land. Furthermore, 
grain is an excellent crop to prepare the land for other crops 
to follow later. 

In most localities there is enough moisture in the soil to 
start the grain at the beginning of the growing season, and the 
number of times that irrigation water must be applied will 
depend upon the factors which have been described. In 
some localities along the Pacific coast and in New Mexico 
and Arizona it may be necessary to apply irrigation water 
during the winter or nongrowing season. In other localities 



IRRIGATION 119 

where there is sufficient rainfall to start the grain, irrigation 
is not practiced until the grain is six or eight inches high. It 
is generally considered better, however, if it is found neces- 
sary to irrigate near the time of planting, to irrigate before 
planting rather than after. 

On light soils with free underdrainage it may not be 
possible to retain the moisture through the winter season, 
in which case irrigation should be practiced near the time of 
planting. It is to be noted, however, that in some localities 
it may be advisable to irrigate after planting, in order that 
the time of planting may not be delayed. The principal 
danger in irrigation after planting lies in the formation of 
crusts. When the crust forms it must be either softened 
with a subsequent irrigation or broken up mechanically by 
means of special rollers or peg-tooth harrows. 

It is considered best not to furnish so much water as to 
grow a large straw crop. Heavy straw crops make a large 
demand upon the soil moisture, and are not essential for 
large crops of grain. Grain is also apt to be of more value 
when grown on straw that does not have a rank growth. It 
is customary, then, to dispense with as much irrigation during 
the growing season as is possible without lowering the 
vitality of the grain. 

In some localities only one irrigation is necessary, and this 
is given at the time when grain is in the milk stage. It 
seems quite important that the grain be supplied with 
abundant moisture at this time. In other localities where it 
is quite dry and where the conditions of soil and climate 
require it, two or more irrigations may be given. 

Alfalfa. One of the great crops of the irrigated land in 
the United States is alfalfa. Like grain, if an ample supply 
of moisture is supplied to the soil before the seed is sown, 
there will be little need of another early irrigation. If the 



120 AGRICULTURAL ENGINEERING 

land be irrigated following the sowing of the seed, the same 
difficulties will be encountered as in the case of grain. 

The first thorough irrigation is usually given after the 
crop shades the ground. After the first crop is harvested, 
each subsequent crop is irrigated, as a rule, but once. Prac- 
tice as regards the time of this irrigation varies in different 
localities. Sometimes the water is applied perhaps a week 
or ten days before the time of cutting. The intervening 
time is necessary in order that the soil may be dried out suffi- 
ciently to enable the mowing machine and hay tools to 
operate successfully. In other localities it is practical to cut 
the crop first and apply the water afterwards. 

Potatoes. Favorable conditions for the growth of 
potatoes are to be found generally throughout the irrigated 
regions in the United States. In the irrigation of potatoes, 
care should be used not to irrigate oftener than is necessary, 
as a low temperature is produced which is unfavorable to the 
growth of potatoes. For this reason the minimum of water 
is supplied, until the time for the formation of the tubers. 
Potatoes seem to thrive best when the irrigations are few 
but thorough, and cultivation is practiced to retain the 
moisture between irrigations. 

Sugar Beets. About two-thirds of the beet sugar 
produced in the United States comes from the irrigated 
sections, and it is one of the crops which can be very success- 
fully grown by irrigation methods. Sugar beets are grown 
over a rather broad range of soils, and irrigation practices 
vary widely with different localities. Where the soil is open 
and the winter season especially dry, winter irrigation is 
practiced; but where there is sufficient amount of moisture 
in the soil to start the crop, irrigation may be omitted 
entirely before the time of seeding. The first irrigation is 
generally delayed as long as possible, or as long as the beets 



IRRIGATION 121 

are making a steady growth. Two or four applications are 
usually made during the growing season. The time of these 
applications is determined by the condition of the plants. 
Just as soon as they begin to suffer for want of water it is 
applied. The last application usually comes within four or 
six weeks before the harvest. This final irrigation is one 
that requires considerable skill in order that it may be given 
at the proper time; for if beets are allowed to mature too 
soon the sugar content will be low. 

Orchard Irrigation. Orchard irrigation is a general 
practice in certain regions. This no doubt is due to the fact 
that irrigation represents intensive agriculture and is well 
suited to the growing of fruits, both large and small, as the 
value of the crop per acre is generally large. It is customary 
in irrigation practice for orchards, to keep the moisture con- 
tent of the soil high enough to insure favorable conditions for 
the growth of the trees at all times. Methods vary more in 
orchard irrigation than in any other. In some localities 
the practice of thoroughly wetting the soil and conserving 
the moisture by cultivation prevails. Sometimes pipes or 
similar conduits are used to give a constant supply of water 
to the soil. Although the last system is not practiced to 
any extent, it is common to find it in some localities. 

QUESTIONS 

1 . In what three ways does soil moisture leave the soil? 

2. In what kind of soil will moisture losses by seepage be greatest? 

3. Discuss four factors that influence the amount of water required 
in irrigation. 

4. Why is thorough wetting better than many light applications? 

5. How much water is required for the common crops in the United 
States, as estimated by Dr. Elwood Meade? 

6. Explain the general methods followed in irrigating grain, 
alfalfa, potatoes, sugar beets, and orchards. 



CHAPTER XX 
SUPPLYING WATER FOR IRRIGATION 

Canals. One of the principal ways of obtaining irri- 
gation water is by the diversion of natural streams by means 
of canals. The design and construction of the canals vary 
widely with localities; but in general the principles involved 
are the same as those involved in the design of open ditches 
or drainage canals, which have been considered in a previous 
chapter. It is customary to compute the capacity of irri- 
gation canals by Kutter's formula, which is given on page 105. 

Diversion canals lead the water of a river away from its 
natural course to the upper side of the area to be irrigated. 
The essential engineering features of a canal consist in 
securing such a grade as to insure a sufficient velocity of 




Pig. 68. Riverside Canal in Colorado before the water was turned 
in for the first time. This canal where shown is 18 feet wide at the 
bottom. 



IRRIGATION 123 

flow to get the necessary capacity and to keep the canal 
clean, or, as usually stated, cause it to "scour." 

The construction of a canal is an important matter. In 
the early stages of irrigation practice in the United States, 
most canals were made with earth embankment, but the 
increase in the value of irrigation water has led to the intro- 
duction of methods to prevent waste from the canals by 
seepage. It is estimated that 47 per cent of the irrigation 
water now used in the United States is wasted in this way, 
and in some cases the losses run as high as 85 per cent. 

Some irrigation canals are ranked among the world's 
greatest engineering achievements. The Cavour Canal in 
Europe cost $20,000,000; its waterway is 66 feet wide and 12 
feet deep, and it crosses the drainage lines of several rivers. 
It passes under the Sesia River in a masonry siphon 820 feet 
long. . There are some large canals in Egypt and India. 
Among them may be mentioned the Chenab Canal, which is 
250 feet wide at the bottom and carries 11 feet of water. 
The main canal is 400 miles long, and has 1200 miles of 
tributary canals. It cost $10,000,000, and it is said to irri- 
gate 2,645,000 acres of land. There are no canals in the 
United States that will compare with it. The Bear River 
canal in Utah cost $1,000,000 and waters approximately 
100,000 acres. The Modesto-Turlock canal system of 
California is designed to water 275,000 acres, and cost about 
$3,000,000. 

Reservoirs. Reservoirs, either natural or artificial, 
obtained by the damming or storage of water in natural 
water courses, are often made the source of supply of water 
for irrigation purposes, inasmuch as water which would 
ordinarily be wasted is held in storage until needed. In 
some localities reservoirs are quite necessary, as streams 
furnish the minimum amount of water during the time when 



124 



AGRICULTURAL ENGINEERING 



irrigation water is needed most. Under other conditions, 
reservoirs are little needed. 

Forests are natural reservoirs to the extent that they hold 
the snow in mountainous countries and prevent a rapid sur- 
face run-off of the water. In some localities the irrigation 
water comes from glaciers, which have been found to regulate 
the supply in a satisfactory and natural way. Thus the 
maximum amount of water is furnished when the weather is 




View of the Roosevelt Dam on the Salt River, Arizona. 
(Bui. 235, Office of Experiment Stations.) 



hottest and the requirements are the greatest. Sometimes 
reservoirs are placed at the end of the canal in order that the 
supply of water may be on hand near the land to be irrigated, 
so that if a sudden demand for water is made which will 
exceed the capacity of the canal, the water from the reservoir 
may be released. 

Reservoirs have been used in connection with irrigation 
since very earry times. In India nearly ten million acres of 



IRRIGATION 125 

land are now irrigated from reservoirs. In Ceylon, the 
Padival Dam is 11 miles in length, and 200 feet wide at the 
base, 30 feet wide at the crest, and 70 feet high in places. 
This dam is said to have cost $6,327,100. It is further 
stated that there are 5000 reservoirs in use in Ceylon. There 
are many reservoirs in use in the United States, some of which 
have been built by private, parties, and others by the 
government. One of the largest of these is the Roosevelt Dam 
on the Salt River in Arizona. This dam, completed in 
February, 1910, has a capacity of 1,824,000 acre feet of water. 

Pumping Water for Irrigation. In many places a supply 
of irrigation water can not be obtained without the aid of 
pumps. Usually water secured by this method is very 
expensive, much more so than the water obtained from 
canals and reservoirs by gravity. There are, however, 
certain advantages in pumping the water for irrigation pur- 
poses. Generally the water supply is under perfect control, 
which is not always the case with a canal or reservoir. Again, 
there can be no controversies over water rights or friction 
with other irrigators who want to use the supply at the same 
time. 

Underground water is the only source of supply in certain 
localities. In some places in the West the soil is so open that 
large streams disappear and flow away underneath the sur- 
face. When this water can be pumped it forms a valuable 
supply of irrigation water. In Egypt much of the water is 
elevated by hand labor either from canals or from the river 
Nile. In California alone, over 200,000 acres are irrigated by 
water which is pumped, and some 400,000 acres are so irri- 
gated in Texas and Louisiana. There has been a marked 
development in pumps during the past few decades. The 
power used includes animal power, steam engines, gas and 
gasoline engines, and electric power. 



126 AGRICULTURAL ENGINEERING 

The cost of pumping water in certain parts of the United 
States has been carefully studied by the United States 
Department of Agriculture. In Santa Clara County, 
California, the cost of pumping water was investigated at 
60 pumping plants. The average amount of water pumped 
per acre was 1.13 feet. The average cost of fuel and labor 
was $4.96 per acre, and the fixed charge was $5.20, making 
the average cost of pumping water $10.16 per acre. The 
average efficiency of the pumps was 41.16 per cent. It was 
found that the cost of pumping was reduced by an increase 
in the size of the plant. The cost of power varies with the 
cost of the fuel. In some localities the steam engine is 
cheaper than gas or gasoline engines, and in others the 
reverse is true. Electricity is more convenient than any 
other power; but unless it can be furnished through a water 
power plant or some other cheap source, it is the most 
expensive. In Arkansas and Louisiana the irrigation water 
for rice culture is pumped by steam. The following table is 
the summary of the cost of pumping water at 17 plants in 
Louisiana and Arkansas, as reported in Bulletin 201, Office 
of Experiment Stations. The general difference in cost at 
the Louisiana plants and those of Arkansas is due primarily 
to the lift or height the water had to be pumped. In the 
Louisiana plants the lift was about 20 feet, and in the 
Arkansas plants about 40 feet. 

Windmills are used quite extensively in certain localities, 
principally in Kansas and California. An investigation of 
the cost of windmill irrigation at Garden City, Kansas, 
indicates that the cost per acre was $2.35. Owing to the 
fact that power is obtained in small units and the cost of 
installation and maintenance is very high in the case of wind- 
mills, it is doubtful if they will be used to any considerable 
extent. 



IRRIGATION 



127 



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128 AGRICULTURAL ENGINEERING 

QUESTIONS 

1. How are canals used to secure a supply of irrigation water? 

2. Why is the construction of a canal important? 

3. Name some of the largest famous irrigation canals. 

4. What are the purposes of irrigation reservoirs? 

5. How do forests act as reservoirs for irrigation waters? 

6. Describe some of the largest irrigation reservoirs which have 
been constructed. 

7. What advantage has pumping over other means of supplying 
water? 

8. How much does it cost to pump water for irrigation under nor- 
mal conditions? 

9. What can be said of windmills as a source of power for pumping 
irrigation water? 



CHAPTER XXI 
APPLYING WATER FOR IRRIGATION 

Principles Involved. In applying irrigation water, con- 
sideration should be given to some of the principles govern- 
ing the wetting, puddling, and washing of the soil. If these 
points are not studied in connection with each type of soil, 
much more water may be used than necessary, and it 
may be used in a way harmful to the crops. A good 
irrigation farmer observes closely the effects of the appli- 
cations on the soil and plant, and continually endeavors 
to improve his methods. When water is applied to the 
surface, it starts to percolate downward and outward. If 
the soil be coarse, the water will travel almost directly down- 
ward, especially if the texture becomes more open or coarser 
as the depth increases. It is then necessary to apply the 
water to the entire surface to get the best results. When 
water is applied to a fine loam underlaid by a subsoil of very 
fine texture, the water percolates downward slowly by grav- 
ity and spreads laterally by capillarity. For this reason the 
water may effectively be applied to these soils in furrows 
some distance apart. 

When the soil is very dry, the percolation downward is 
less rapid than when it is more moist. This is accounted for 
by the fact that the air in the soil must be displaced before 
the water can travel downward. This takes time, and for 
this reason a soil will not take water as rapidly when dry as 
when moist. 

In applying irrigation water, great care should be taken 
not to puddle the soil, that is, to cause the crumb structure to 



130 AGRICULTURAL ENGINEERING 

be so broken down as to allow the soil particles to run to- 
gether and form a compact mass. Soil in such a condition is 
said to be water-tight. The air cannot enter a soil of this 
kind, and an aerated soil is essential in furnishing favorable 
conditions for plant growth. If too much water is applied 
to the soil, it becomes water-logged and suffers for the lack 
of air in the same way. 

Preparing Land for Irrigation. As irrigation water is 
usually applied by the aid of gravity, great care should be 
used in preparing the surface ground and the ditches and 
small laterals necessary to convey the water over the fields. 
The proper slope must be given to the surface to give an even 
distribution of the water. For this reason one of the largest 
items of expense involved in bringing land under irrigation is 
the cost of preparing the land. Usually irrigable land is 
covered with some sort of growth which must be removed. 
It costs from $1.50 to $4 per acre to remove sage brush, which 
is usually found on the land in the arid sections of the United 
States. The land must be thoroughly gone over with graders 
and other leveling machines and worked until the surface is 
made a perfect plane. 

Dr. Elwood Meade states that the cost of preparing the 
land for irrigation in the United States varies from $3 to $30 
per acre. The following table shows the average cost of 
preparing land for different methods of irrigation : 

Check method $ 3.60 

Flooding method 2.75 

Furrow method 3.50 

Basin method 4.50 

Methods of Applying Water. There are many methods 
of applying water to irrigated crops, and nearly all are 
practiced in the United States. The method to be used in 
any particular case depends largely upon the nature of the 



IRRIGATION 



131 



ground, the crops grown, the amount of water available, kind 
of soil, and other conditions. 

The Flooding Method. One of the more general methods 
of application is known 
as the flooding system. 
It is generally used on 
land when it is first re- 
claimed, even though 
another method is in- 
tended to be used later. 



■M 



Fig. 



70. Flooding method of irrigation. 
(Sep. 511, U. S. Dept. of Agr.) 



Preparing the ground 
for flooding consists in 
leveling, grading, and smoothing, so that the water will 
flow readily over it in sheets. To distribute the water, small 
field ditches, or laterals, are located along the best routes. 
These small ditches are usually from 50 to 100 feet apart, 
and they generally follow grade lines, or contours. Where 
wwkg exa- little care is used to control the flow 
of the water, the practice is said to be 
"wild flooding." The small ditches 
are made with a double moldboard 
plow, which turns a furrow on either 
side. To cause the water to overflow 
from the ditch to the side, a dam 
must be put in place. This con- 
sists usually of a piece of canvas 
nailed along one edge to a strip of 
wood. In other cases, the ditch may 
be dammed by simply building up a 
small ridge of earth across the ditch. 
The Check Method. The check method of applying 
water consists in dividing the fields into sections each having 
a comparatively level surface and bordered on all sides by 




Fig. 71. A canvas dam. 
This dam has an opening 
to divide an irrigating 
stream. (Bui. 203, Office 
of Experiment Stations.) 



132 



A GUI C UL T URAL ENGINEERING 




as dam in i 
I". S. Dept. 



an opening is made 
check and the water 
allowed to flow in 
until each is covered 
to the desired depth. 
Where the check 
method is followed, 
it is customary to 
have small wooden 
outlets from the ditch 
into the checks, with 



low, flat levees, or ridges. 
Into these checks the 
water is turned. On level 
ground these sections or 
checks may be made rec- 
tangular; but on sloping 
ground the ditch for sup- 
plying the water must fol- 
low the contour lines, in 
which case they are said 
to be contour checks. 
In applying the water, 
from the ditch into the side of each 




Check method of irrigation. 
U. S. Dept. of Agr.) 



(Sep. 514, 




valves which can be 
operated to close the 
opening when de- 
sired. 

Basin Method. 
The basin method is 
quite similar to the 
check method. It 
is used principally 
in the irrigation of 



IRRIGATION 



133 




Border method of irrigation. 



trees. A basin is provided around the tree, with a suitable 
ridge to hold the water, which is then turned in until a suffi- 
cient amount is applied. 

Border Method. The border method is also similar to 
the check method in 
that the land is di- 
vided into long strips, 
and the water is 
turned into these 
from a ditch at the 
end or along the bor- 
der. It is easy to 
see that by arranging 

these long strips the work necessary in preparing ridges is 
reduced. 

Furrow Method. The furrow method of applying irri- 
gation water consists in turning the stream of water into 
furrows between the rows of intertilled crops. It is more 
generally employed than any other method, with the excep- 
tion of flooding from field laterals. The distance between 
furrows will depend upon the character of the soil. It is 
customary to provide small openings or pipes in the ridge 

at the side of the 
supply ditch by 
which the water may 
be turned into the 
furrows. 

Subirrigation. 
Upon first thought 
it would seem that 
subirrigation, or wa- 
ter applied to crops from pipes laid beneath the surface, 
would be an ideal system. This is not the case, as such a 




Fig. 76. Manner of placing tubes in ditch 
bank for furrow irrigation. (Farmer's Bui. 373, 
U. S. Dept. of Agr. ) 



134 



AGRICULTURAL ENGINEERING 



system is not only expensive to install, but also quite extrav- 
agant in many cases in the use of water. This is due to 
the fact that the water tends to percolate downward from 
the opening and so does not saturate the soil satisfactorily. 
Spraying Method. Where irrigation is practiced in a 
small way the water may be applied by spraying. This 
system provides surface pipes containing water under 
pressure, whch may be discharged through nozzles in such a 
way as to cover the entire surface. Often the pipes are 
arranged so as to revolve, turning the nozzles about in such 
a way as to discharge in different directions and thus reduc- 
ing the amount of pipe required. 

The Measurement of Water. Most of the water used 
in irrigation is sold to the farm owners, which fact necessi- 
tates that methods be devised for its measurement and regu- 
lation. In addition, 
the irrigator should 
know something defi- 
nite about the amount 
of water applied, in 
order that he may de- 
termine whether or 
not it is being used as 
efficiently as it should 
be. 

Units of Measure- 
ment. One of the most 

7 7. A Cippoletti weir with water regis- satisfactory Units of 

ter in place for measuring and recording: the J 

head of water over the lower edge of the weir, measurement f rOHQ the 
(.Bui. S6, Office of Experiment Stations.) 

standpoint of the agri- 
culturist is the acre-inch, which is the amount of water required 
to cover an area of one acre one inch deep. Thus, ten acre- 
inches is sufficient water to cover an acre ten inches deep, 




IRRIGATION 135 

or ten acres one inch deep. The principal advantage of this 
unit lies in the fact that a direct comparison may be made 
between the irrigation water applied and a similar amount 
of rainfall. Where water is delivered from a canal, it is 
necessary to use a unit which will indicate the rate of delivery. 
The cubic foot per second is a unit in common use, and is 
easily understood. The miner's inch, used in many states, 
is a unit whose value varies very much. In Idaho, Nevada, 
and Utah, laws have been enacted defining a miner's inch 
as 1-50 of a cubic foot per second. In Arizona, it is 1-40 
of a cubic foot per second, and in Montana a unit having 
the same value is called a statute inch instead of a miner's 
inch. In Colorado, a cubic foot per second is equal to 38.4 
statute inches. Water is usually measured by weirs, which 
are notches of a certain form through which the water is 
allowed to flow. A form of weir in general use is known as 
the Cippolletti. The amount of water flowing through such 
a weir may be determined from the height, or "head," of the 
flow. 

QUESTIONS 

1. What are some of the principles involved in applying irrigation 
water? 

2. What are some of the essential features of preparing land for 
irrigation? 

3. How does the cost of preparing land for irrigation vary with 
methods of irrigation? 

4. Describe the flooding method of applying irrigation water. 

5. Explain the check method of applying water. 

6. Describe basin and border irrigation. 

7. How is irrigation water applied in furrows? 

8. Why is subirrigation not generally satisfactory? 

9. How is irrigation water applied by spraying? 

10. What are the units in general use for measuring irrigation 
water? 

1 1 . What is a weir? 



CHAPTER XXII 

IRRIGATION IN HUMID REGIONS, AND SEWAGE 
DISPOSAL 

Irrigation is generally practiced in those regions where the 
natural rainfall is so small as to make it quite impossible to 
grow crops without supplying water artificially. Here irri- 
gation is an absolute necessity. In other localities, it may 
not be a necessity, but it may be practiced profitably to sup- 
plement rainfall, thus securing larger yields. As agriculture 
becomes more intensive, it is to be expected that irrigation 
of this nature will become more common. 

The regions in which the rainfall is very small are said 
to be arid; those having sufficient rainfall to produce good 
crops under normal conditions are said to be humid; and the 
regions in which the rainfall is scanty or limited are said to 
be semiarid. It is to be expected that supplementary irri- 
gation will be practiced more in semiarid regions than in 
humid regions. However, if a careful study be made of the 
distribution of rainfall in many so-called humid regions, it 
will be found that in many j^ears when the demand for 
moisture is the greatest, the rainfall is insufficient. A study 
of the rainfall at Philadelphia, by Mr. R. P. Teele, of the 
Office of Experiment Stations, shows that although the 
average rainfall for that locality is large, the records indicate 
that there were periods of drouth during 88 per cent of the 
seasons for the 70 years covered by the investigations, which 
dry spells caused injury to the crops that had short growing 
periods. The investigations also showed that all crops 
received too little water during a third of the years. 



IRRIGATION 137 

In Europe, irrigation has been practiced for ages in 
regions having rather large rainfall. Meadows and pastures, 
especially, are irrigated very successfully, and this is com- 
monly practiced in Great Britain, Holland, Germany, 
Switzerland, Italy, and France. 

In some countries where there is much sunshine, phe- 
nomenal crops are grown through irrigation. It is reported 
that in Italy, marcite, a meadow crop made up of a mixture 
of clover and Italian rye grass, will yield from ten to fifteen 
tons per acre of a cutting, for eight to ten cuttings per year. 

There are many small irrigation plants through the humid 
portions of the United States. Data collected by the irriga- 
tion investigations of the United States Department of 
Agriculture indicate that about 800 acres of meadow land 
are irrigated in the humid regions of the United States. 
Most of the water used is obtained from springs and through 
the diversion of streams by small canals or dams. This 
water is let over the meadows in small ditches or laterals, and 
is spread over the same in a manner similar to the check 
method of irrigation. Irrigation is also generally practiced 
in the growing of small fruits, which are seriously injured 
by drouths that come at the time when the fruit is forming. 

The truck farmers have also found irrigation a profitable 
insurance against loss through drouth. Professor F. H. 
King, of the Wisconsin experiment station, conducted some 
very interesting experiments in irrigation at Madison, Wis- 
consin. Over a rather long term of years, the average 
increase in the yields of grain was 26.93 bushels per acre. 
The increase in the yield of clover hay was 2}/^ tons per acre; 
and of potatoes, 83.09 bushels per acre. The cost of irrigat- 
ing the land was $6.80 per acre, which cost did not include 
the interest on the first investment for the plant. These 
gains are made up from the average yield for the State of 



138 AGRICULTURAL ENGINEERING 

Wisconsin and therefore are no doubt large, inasmuch as the 
nonirrigated crops do not generally receive the attention 
given to those which are irrigated. 

Irrigation for Sewage Disposal. In many localities the 
disposal of sewage water from cities is an important problem. 
This is especially true of cities which are not situated near 
large bodies of water or streams into which the sewage may 
be discharged. In these cases, sewage irrigation must be 




Furrow irrigation with sewage water. 



resorted to, and this not only provides a convenient method 
of disposal, but it may be made a matter of profit. Perhaps 
there is no way of disposing of sewage more satisfactorily 
than by applying it to the soil. The organic matter in 
sewage water is quickly purified through the agency of soil 
organisms, when it is applied to the soil in a skillful manner. 
The crops grown by sewage irrigation vary widely, and 



IRRIGATION 



139 



include grasses, grains, potatoes and garden truck. Of 
these, grasses is the most generally grown; Italian rye grass, 
especially, thrives under this form of irrigation. The success 
of sewage irrigation indicates that it could be practiced more 
generally than it is at present. 

For several years, experiments in sewage irrigation were 
conducted at the Iowa experiment station, in co-operation 
with the irrigation investigations of the United States Depart- 
ment of Agriculture. The following table is a summary of a 
part of the results obtained. Two plots of each crop were 
grown under the same conditions, except that one was irri- 
gated with sewage water and the other was not irrigated at all. 



Summary of irrigation experiments in Iowa, showing increased yields by 
the use of sewage water. 



Kind of crop 


Year 


Yield per acre; 
not irrigated 


' Amt. of 

sewage 

water 

applied in 

irrigation 


Yield per acre 

irrigated 

area 


Increase 
yield per 
A. by irri- 
gation 


Cabbage 

Corn 


1907 
1907 
1907 
1908 
1908 
1908 
1909 
1909 
1910 
1910 
1910 


63840 lbs. 
57.8 bu. 
41.4 bu. 
3.15 tons 
11.25 tons 
150.2 bu. 
29. bu. 
6.67 tons 
.13 tons 
1.42 tons 
39.1 tons 


7 in. 
7 in. 
13.21 ft. 
5.41 ft, 
7.08 ft. 


70430 lbs. 
59.8 bu. 
54. bu. 

3.49 tons 
12.75 tons 
181.5 bu. 
34. bu. 

5.6 

1.32 tons 

3. tons 
59. tons 


9.5% 
3.4% 
30.4% 
10.7% 
13.3% 
20.8% 
17.2% 
—16.0% 


Barley 

Rye grass 

Beets, sugar. . . . 

Potatoes 

Barley 

Alfalfa 

Blue grass 

Timothy. ..:... 
Beets 


111-2% 
50.9% 



During the years 1907 and 1908, irrigation was given 
only when the crop seemed to be in need of moisture. In 
1910 a larger amount of water was used. 



141) AGRICULTURAL ENGINEERING 

QUESTIONS 

1. What is meant by humid, semiarid, and arid regions? 

2. Why is irrigation profitable in humid regions? 

3. How have experiments proven that yields may be increased in 
humid regions? 

4. Does irrigation furnish a satisfactory means of disposing of 
sewage water? 

5. What crops can be profitably grown with sewage irrigation? 

REFERENCE TEXTS 

Irrigation Engineering, by H. M. Wilson. 

Irrigation and Drainage, by F. H. King. 

Irrigation Institutions, by Dr. Elwood Meade. 

Irrigation Farming, by L. Wilcox. 

Primer of Irrigation, by D. H. Anderson. 

Bulletins of the United States Department of Agriculture. 



PART FOUR -ROADS 



CHAPTER XXIII 
IMPORTANCE OF ROADS 

History. The object of a road is to furnish a way for 
travel and the transportation of products. The art of road 
construction runs back before the time when history was 
written, and roads have appeared in a country whenever its 
people have shown a tendency to become civilized. 

There is abundant evidence at hand to show that a paved 
road existed in Egypt as early as 4000 years b. c. No doubt 
the material for the great pyramids was transported over a 
part of this road. Much of the history of Carthage and 
Rome relates to the construction of their roads, which were 
used for the transportation of soldiers and supplies. The 
success of the Roman Empire as a great nation is largely due 
to its system of improved roads, over which its armies could 
be moved quickly. Ancient Rome had no less than 372 
great roads, aggregating about 50,000 miles, and which, it 
has been estimated, would cost under modern conditions as 
much as $5,000,000,000. All of the civilized nations through- 
out the world have given the matter of road construction 
careful attention. 

The Extent of Our Roads. There are in the United 
States 2,150,000 miles of public roads. About one-half of 
this mileage, however, is but little used, and no doubt in 
time a part will be found unnecessary and will be discon- 
tinued. 



142 AGRICULTURAL ENGINEERING 

Benefits of Good Roads. The benefits of good roads to 
agriculture are far-reaching and are worthy of careful and 
extended study. The benefits are largely financial in char- 
acter, and so the value of good roads may be estimated in 
dollars and cents. There are other benefits which may be 
styled social, and are those which tend to add to the comforts 
of country life. 

FINANCIAL BENEFITS 

Cost of Transportation. The most important and funda- 
mental benefit to be derived from a system of good roads lies 
in the reduction of the cost of transportation of farm and 
other products which must be hauled over them. 

Referring to Bulletin 49 of the United States Office of 
Public Roads, it is found that during the crop year of 1905 
and 1906 there were 42,743,500 tons of farm products, con- 
sisting of barley, corn, cotton, flax seed, hemp, hops, oats, 
peanuts, rice, tobacco, wheat, and hay, hauled over the 
roads from the farms to the shipping points. This estimate 
does not include the transportation of products from the 
town back to the farm, nor does it include live stock, truck- 
farm products, and fruit. A careful investigation by the 
Office of Public Roads indicates that the present cost of 
transportation is about 25 cents per ton mile, that is, the 
cost of hauling one ton one mile. If a small saving could be 
secured in this cost of transportation per ton mile, the aggre- 
gate saving for a year would be enormous. 

With a system of good roads it is possible to make a great 
reduction in this cost of transportation. The cost varies 
with the kind of road. The investigation shows that over 
broken-stone roads in good order the cost is only 8 cents per 
ton; on broken-stone roads in ordinary condition, the cost is 
11.09 cents; on earth roads, with ruts and mud, the cost is 



ROADS 143 

39 cents; and on sandy roads, the cost is as much as 64 cents 
per ton mile. The average haul for farm products in the 
United States is about 9 miles. It is estimated by Mr. L. W. 
Page, director of the United States Office of Public Roads, 
that if the cost of hauling in the United States could be 
reduced from 25 cents to 12 cents per ton mile, the annual 
saving in moving the twelve principal farm crops would 
amount to $51,000,000. He further estimates that the total 
amount of freight hauled over country roads in a year 
reaches 265,000,000 tons, and that the total cost of haul- 
ing this on the roads approximates $500,000,000. In this case 
the total saving in reduction of the cost of hauling from 25 
cents to 12 cents per ton mile would be $250,000,000 annually. 

In this connection, attention is called to the fact that it 
would not be practical to improve all country roads. Mr. 
Page estimates that the traffic is such that the cost of hauling 
freight could be reduced to 15 cents per ton mile if 25 per 
cent of the roads were improved. He estimates that the 
total cost of improving this percentage of the total mileage 
of roads would be $2,000,000,000. 

A striking example of importance of country roads is set 
forth by the fact that it costs the American farmer 3.06 
cents more per bushel to haul his wheat crop a distance of 
9.4 miles to market, than it costs to ship by regular steamship 
lines from New York to Liverpool, a distance of 3100 miles. 

Influence on Markets. Good roads have a decided 
influence upon markets in several ways. First, a wider 
variety of crops may be grown, and marketed at the center 
from which good roads radiate. This tends to increase about 
cities the area in which certain crops, such as fruit and 
truck crops, can be grown. This is also true of dairying, as 
a dairy farm can be located farther from the city, if good 



144 AGRICULTURAL ENGINEERING 

roads are provided between the farm and the city, enabling 
the farmer to deliver his products quickly and cheaply. 

Again, good roads permit the marketing of farm products 
when the prices are most favorable. In many localities, 
when prices are best the farmer is unable to deliver his 
crops, owing to the fact that the roads are impassable. 

Also, good roads furnish to the farmer a wider choice 
of markets. With good roads prevailing, it is possible for 
him to deliver his products to any one of several centers. 
Good roads tend to equalize the supply of produce on any 
given market between favorable and unfavorable seasons of 
production. Lastly, good roads tend to equalize local mer- 
cantile business throughout the different seasons of the year. 
In some instances little business can be done when the farmers 
are unable to get into town on account of the bad roads. 

Good roads tend to equalize railroad traffic. Often dur- 
ing the period of bad roads, farm products are not delivered, 
and the railroads have little to do. Then when the roads 
become passable to heavy traffic, farmers sell their products 
in such large quantities as to cause a congestion of traffic. 

SOCIAL BENEFITS 

Social Benefits. Perhaps of equal importance with the 
financial benefits to be derived from the system of good 
roads, are the social benefits. Good roads permit more easy 
intercourse among country people, and between country 
people and city people. Good roads place the farm nearer 
the city, thus overcoming to a certain extent some of the dis- 
advantages of country life. They are also a factor in assist- 
ing in the development of the consolidated rural school, and 
facilitate the rural mail delivery. The United States Post 
Office Department will not establish or continue a rural 



ROADS 145 

mail route where the roads are not maintained at a certain 
standard. 

Value of Farms. It is often stated that good roads tend 
to increase the value of farms ; and some instances are referred 
to where, upon the completion of a good road past a farm, its 
selling value was at once materially increased. No doubt 
this can be considered the measure of the value of the bene- 
fits which have been discussed. 

Requisites of a Good Road. A good road is one over 
which travel may take place with ease and comfort, and one 
over which freight or products may be hauled at a low cost. 
Furthermore, a good road must not be prohibitive in cost, 
and must require a minimum of attention for its maintenance. 
The following are some of the more important features which 
should be considered : 

Smoothness. No road can be considered a good road 
unless it presents a smooth surface over which vehicles may 
travel without jar or vibration. Smoothness is also essential 
to the moving of loads with the least effort. 

Rigidity. When a loaded vehicle rests upon a road sur- 
face, the wheels sink into the surface more or less. If the 
road surface is soft, the wheels will sink in deeply, and the 
vehicle, as it is drawn forward, will be compelled to roll 
against an incline. The amount of resistance which the load 
furnishes varies with the depth that the wheels cut into 
the surface. Thus, the road which will most prevent the 
wheels from cutting in will furnish the least resistance. 

When a loaded vehicle is moved up an incline, it is noticed 
that the resistance is increased proportionately to the grade. 
Thus if a load of 1000 pounds be moved up a 10 per cent 
grade, an extra force equal to 10 per cent of the load will be 
required to overcome the resistance due to the grade. It is 



146 AGRICULTURAL ENGINEERING 

here necessary to explain that a grade of 10 per cent is one 
which has a rise of 10 feet in 100 feet of length. 

Costs. A good road must not cost more than a certain 
amount, or the value of its service will not cover the interest 
on the investment. Thus the best road for certain conditions 
may be one that is comparatively cheap, inasmuch as the 
amount of traffic will not justify the expenditure for a more 
expensive road. A good road mil be durable, and will 
require little attention to repair it. For this reason great 
care should be used to see that the road is well constructed 
and that durable materials are used. 

QUESTIONS 

1. What is the object of a road? 

2. What is the mileage of roads in the United States? 

3. What two classes of benefits may be derived from good roads? 

4. What is meant by the "ton mile"? 

5. What is the average cost of transportation in the United States? 

6. How does the cost of transportation vary with the kind of road? 

7. In what way will good roads influence the markets? 

8. How may good roads be of benefit in a social way? 

9. What are the requisites of a good road? 

10. How much money, according to the estimate of Mr. Page, 
could be spent each year in the improvement of roads? 

Note. The student should obtain statistics in regard to roads in 
his own state, county, and township; the mileage, the funds spent, etc. 



CHAPTER XXIV 
EARTH ROADS 

Extent. Of the total mileage of roads in the United 
States, about 2,000,000 miles are unimproved, or earth 
roads. It is evident that a large percentage of these roads 
will remain unimproved for a long time, and for this reason 
earth roads are worthy of the most careful attention. By 
the term " earth roads" is meant roads made of native soil 
and whose surface is loam or clay. Obviously the earth 
road is the cheapest form of road. It is possible to construct 
a fairly good road out of native soil, and such a road in most 
cases furnishes the very best foundation for an improved 
road with a hard surface of sand or gravel. 

Construction of an Earth Road. The subject of earth 
roads naturally divides itself into two divisions, earth-road 
construction and earth-road maintenance. The first applies 
to the preparing, constructing or building of the road, and the 
last to its maintenance or repair. 

Drainage. It is often stated that the construction of 
earth roads consists primarily in providing adequate drain- 
age. When considered in the broadest sense, drainage 
would include not only underdrainage, but also surface 
drainage. Underdrainage is quite necessary in any kind of 
road, and especially in an earth road, and if not provided 
naturally it should be provided artificially. In constructing 
earth roads it is desirable to maintain as hard a surface as 
possible with the materials used, and water tends to soften 
them. The supporting power of earth depends largely upon 
the dryness of the soil. A good surface may be prepared, yet 



148 



AGRICULTURAL ENGINEERING 



if there is water beneath it the water will come up by capil- 
lary action and soften the road until its supporting power is 
lost. Again, the action of frost is greater when the road sur- 
face is full of water. Freezing causes the roadbed to expand 
and heave, tending to soften it. Thus it is highly important 
that soil in which the ground water stands within 3 or 4 feet 
of the surface be drained with a tile drain. This is generally 
accomplished by placing a line of tile at one side of the road, 
under the side ditch, although sometimes it is placed beneath 
the middle of the road. The former location is preferable 
for several reasons. First, the ditch does not need to be as 
deep. Second, in case of repairs the tile is easier to get at, 
than it would be if it were located underneath the middle of 
the road ; and if it is found necessary to take it up, traffic will 
not be interfered with. Third, in a properly constructed 
earth road the water which flows on the surface is conveyed 
rapidly to one side by the slope or crown of the road. 




Fiasr Class 

Section in Cut 




Fig. 79. Cross sections of earth roads, as recommended by the Iowa 
Highway Commission. 

Where thorough drainage is needed, it may be advisable 
to place a tile line at each side of the road, but under ordi- 
nary circumstances one line of tile ought to be sufficient. In 
providing tile drainage, care should be taken to see that the 
tile is of ample size to meet the requirements of the area to be 



ROADS 149 

drained. Where the road is on a hillside, seepage water, 
which often causes a wet road, may be intercepted by locat- 
ing the tile line at the upper side. 

Side Ditches. In the construction of earth roads, side 
ditches are provided to receive the water and carry it along 
the road until points are reached where it may be discharged 
into natural channels. An even grade or slope should be 
given, so that the water will not collect in puddles in the side 
ditches. It is impossible to maintain a good road under 
such conditions. These ditches should be of sufficient 
capacity to care for the water. They should be so con- 
structed as not to be dangerous to vehicles when driven into 
them. The outside bank should not be so steep as to cause 
the soil to cave into the ditch, and partially stop the flow of 
water. Side ditches should be easily constructed and cleaned 
with the common road machines. It is desirable that they 
be of such form as to permit the mowing of weeds in them with 
a common mower. In some localities it is desirable that the 
side ditches have a form that will hold snow during the winter 
months, facilitating sled traffic. A good form for the side 
ditch is the V shape, with the outside bank having a slope of 
13^ to 1 and the inside bank with a slope of 3 to 1, as shown 
in the accompanying cross section of an earth road. 

The Crown. It is highly important that the middle of 
the earth road be higher than the sides, which will cause the 
surface water to drain quickly to each side and not lie on the 
surface and soften it. This oval part of the road is usually 
called the crown. The road should not only be oval, but 
should also be smooth so that the water will not lie in pockets 
on the surface. It is not so important that the crown be of a 
particular form, except to secure uniformity of construction, 
but it is important that it be smooth and that there shall be 
some slope to each side. If the slope be too steep, the travel 



150 AGRICULTURAL ENGINEERING 

will have a tendency to concentrate at the middle of the road, 
which in a very short time causes ruts. A slope of % to 
1 inch to the foot, as shown in the accompanying sketch, is 
customary. 

Road Maintenance. In order to keep the earth road in 
the best possible condition, it is necessary that the oval 
shape of the surface be maintained, and that ruts be pre- 
vented from forming. To do this, the roads must receive 








Fig. SO. An earth road maintained in good condition by the road drag - .' 

practically constant attention. The best device for keeping 
an earth road smooth is the road drag. 

The Road Drag. The road drag is a device for smoothing 
earth roads. It is sometimes called the King drag, as its 
use has been urged by D. Ward King, of Maitland, Missouri. 
Its construction will be described later. The drag is usually 
drawn with the blades at an angle with the direction of travel, 



ROADS 151 

so that the soil which is carried out by the mud that sticks 
to the wheels may be replaced and the general wear repaired. 
Width of Earth Roads. The right of way provided in 
most states for public roads varies from 40 to 66 feet. This is, 
perhaps, more land than is needed for that purpose, in most 
instances. It is unusual to improve more than about 36 
feet of this right of way, making each side ditch about 9 feet 
wide and the crown proper 18 feet wide. 




Fig. 81. A typical condition of an earth road on which the drag has 
not been used. 

Earth Road Grades. The grade of earth roads may be 
greater than those of roads surfaced with stone or similar 
material, because the loads which are hauled on level earth 
roads are not as great as those usually hauled on hard roads, 
owing to the fact that the rolling resistance due to the softer 
road surface is greater. Thus the smaller loads adapted to 
earth roads may be hauled up steeper grades with the same 



152 AGRICULTURAL ENGINEERING 

increase of effort that larger loads require on lower grades. 
It is of course desirable to keep the grade as low as possible, 
but different localities have different standards for the maxi- 
mum grade. This maximum varies from 10 per cent for 
roads used but little, to 4 and 6 per cent for those on which 
the traffic is heavy. 

The drag can be used to the best advantage following 
rains, when the soil is still moist. It then has a better 
smoothing action and the earth scraped into the low places 
is easily compacted. Roads which are dragged continu- 
ously for a term of years become very dense and hard. 

QUESTIONS 

1. What is the mileage of earth roads in the United States? 

2. Why should earth roads be given careful attention? 

3. What are the two divisions of the subject of earth roads? 

4. Why is the drainage of earth roads important? 

5. How much slope should the crown of the road have toward the 
side ditches? 

6. Is it important that the crown be of any particular shape or 
form? 

7. What will be the result if the sides of the crown are given too 
much slope? 

8. How should earth roads be maintained? 

9. What is a good width for a country earth road? 

10. What should be the maximum grade for earth roads? 

11. Explain the action of the road drag. 



CHAPTER XXV 
SAND-CLAY AND GRAVEL ROADS 

Clay Roads. By careful construction and continued care 
an earth road may be made fairly satisfactory. This is true 
where such a road is made of clay. The construction and 
maintenance of a clay road consists primarily in providing 
drainage. Such a road should be kept as dry as possible. 
It should have sufficient slope from the center toward the 
sides to insure quick surface drainage to the side ditches; 
and as far as practical, underdrainage should be provided to 
carry off the water that comes up from below. At best, how- 
ever, the clay road is not highly satisfactory. During the 
wet weather it becomes soft, and owing to the stickiness of 
the clay the surface is rapidly destroyed. 

Sand Roads. In many localities the surface of the roads 
is composed largely of sand. Sand roads present an entirely 
different problem from clay roads; they are at their worst 
when dry, and are best when moist. For this reason some 
skilled highway engineers advise that sand roads be made 
flat, or without a crown. Straw, sawdust, and other mate- 
rials are added to the sand in order to hold the moisture, 
causing the sand to remain as compact as possible. It is 
also noticed that sand roads are best when shaded by trees. 

Sand-Clay Roads. Where clay roads and sand roads 
exist in the same locality, it has been observed that nearly 
always there is a good piece of road between the stretch of 
clay road and the stretch of sand road. This would indicate 
that a mixture of sand and clay makes a better road surface 



154 AGRICULTURAL ENGINEERING 

than either one alone, and it has been demonstrated fully 
that this is true. In constructing the sand-clay road, suffi- 
cient clay is added to the sand, or sand to the clay, as the case 
may be, to fill the open spaces between the sand particles 
with clay, causing the mixture to form into a very dense and 
impervious layer. Tests should be made to determine the 
amount of clay which must be added to the sand, or the 
amount of sand which must be added to the clay. The re- 
quired material is hauled to the roads to be improved and the 
mixture made by plowing, harrowing, and rolling. If after a 
time it is noticed that the road surface balls up and sticks to 
the wheels of the vehicles driven over it, there is not a suffi- 
cient amount of sand in the mixture. On the other hand, if 
during the dry weather the surface becomes loose, it would 
indicate that more clay should be added. Sand-clay roads 
are very cheap, often their cost does not exceed more than 
$100 to $200 per mile and seldom exceeds $400 per mile. 
The sand-clay road is simply a step toward the gravel road. 

Gravel Roads. Gravel consists of particles of stone 
which have been rounded by the action of water and ice, 
and which are deposited in banks. Gravel of the right kind 
is a material from which a very satisfactory road may be 
constructed. It is not suited, however, to heavy traffic. 
It is suited to average country conditions, and in many 
localities where gravel can be had conveniently it is the most 
desirable material to use. 

Durability of Gravel. Gravel that is satisfactory for the 
surfacing of roads should be durable and not so soft as to be 
ground into dust by much traffic, neither should it be so 
brittle as to be easily shattered or broken. As a general 
rule, most gravel may be depended upon to be fairly durable, 
for if it were not so it would not exist as gravel after having 



ROADS 155 

undergone the test. placed upon it in its formation and trans- 
portation by water and ice. 

Size of Gravel. It is desirable that the pebbles in the 
gravel for road surfacing be not too large. It is customary 
to screen out all pebbles or stones larger than % to 1 inch in 
diameter. In some cases where larger pebbles exist they 
are screened out and used for the first courses in the con- 
struction of the road bed. If large pebbles or stones are 
left in the gravel they are quite apt to come to the surface 
through the action of the traffic and of frost. Gravel 
should also vary in size, so that there will be small pebbles 
to fil !the open spaces between the larger ones, and in 
turn the space between the smaller pebbles should be filled 
with sand grains. When the gravel varies in size in this 
manner a very dense mixture is obtained, which is ideal for 
road material. In some cases where the different sized 
pebbles do not exist naturally in the proper proportion to 
make a dense mixture, it may be profitable to screen the 
gravel and remix it more nearly as it should be. 

The Binder. In order that the gravel shall form a 
satisfactory surfacing material for a road, it must contain or 
be mixed with some material which will hold the pebbles 
together. In most instances this binding material is clay. 
Clay exists to some extent in all gravels. When the gravel 
will stand vertically in the bank, and when it resists the 
action of frost and must be loosened with a pick, it is quite 
likely to contain the proper amount of binding material. If 
a sufficient amount of clay is not present to fill the open 
spaces between the pebbles and cause them to be packed 
into a dense structure, additional clay should be added. 
Clay has several characteristics which recommend it as a 
binding material. It is cheap, can be easily reduced to a 
finely divided state, and is usually found to a more or less 



156 AGRICULTURAL ENGINEERING 

extent in the gravel. On the other hand, it has some 
undesirable characteristics. It loses its binding power when 
dry, and is susceptible to the action of frost. In many cases 
other kinds of binders are used. Stone dust has excellent 
cementing properties and is considered better than clay, 
but is more expensive. As will be explained in the chapter 
on stone roads, automobiles have introduced many new 
problems in connection with road construction. Many 
forms of binders and dust preventives are being experi- 
mented with. Bitumen, tar, crude oils, and chlorides are 
used to hold the gravel together. 

Drainage. A good gravel road must be thoroughly 
underdrained if it is to be satisfactory. The method of 
draining does not differ materially from that described for 
earth roads. Many mistakes have been made by those 




Fiist Class 

3e<l,o~,„ Cut 

Fig. S2. Cross section of gravel road. (Iowa Highway Commission.) 

having the matter of road construction in hand, by applying 
surfacing material to a road which needed underdrainage 
badly, and so the material did not produce the results which 
were hoped for. The ground water coming up from below 
softened the surface, and the gravel was forced down into 
the earth until it entirely disappeared. Gravel roads should 
have sufficient amount of crown or lateral slope to secure the 
rapid drainage of all surface water to the side ditches. The 
amount of slope is usually given as 3^ to 1 inch to one foot of 
width. 

Surface Construction. There are two general methods of 
surfacing roads with gravel. The cheapest method is known 



ROADS 



157 



as surface construction. In this method the gravel is hauled 
and dumped on the prepared road bed, which usually is an 
earth road, and the packing is left to the traffic. Sometimes 
little attention is given to the matter of smoothing and 
spreading the gravel. 

The thickness of surface gravel applied in this manner 
varies from 3 to 6 inches at the center, usually tapering down 
to a less thickness at the sides. It is considered the best 
practice to apply the gravel in two layers; thus if the total 
thickness of six inches of gravel is to be applied, it will be 
spread in two layers 
three inches each. After 
the first has been spread, 
sufficient time should be 
allowed for the traffic 
to pack it quite thor- 
oughly before the second 
layer is spread. 

Trench Method. In 
the trench method the 
road surface is carefully 
graded and rolled to re- 
ceive the gravel. Usually 
banks are provided at 
the side which will hold 
the gravel on the road 
proper. In trench con- 
struction the gravel is usually placed in two or more layers, 
the first being composed of coarse pebbles, and is thor- 
oughly rolled with a heavy roller before the other courses 
are applied. This form of construction gives a finished 
road at once, and for this reason is more desirable than the 
surface method. This is much more expensive, however. 




Fig. S3. Model of a gravel road illus- 
trating the trench method of construction. 
A shows prepared sub-grade: B, first course 
of gravei ; C. upper course of gravel. (Bui. 
36, Office of Public Roads, U. S. Dept. of 
Agr.) 



158 • AGRICULTURAL ENGINEERING 

Cost of Gravel Roads. The cost of gravel roads varies 
widely, depending largely upon the availability of gravel. 
The method of construction is another important factor. 
The amount of gravel used varies widely with different con- 
struction. In some cases as little as 1^10 of a yard of gravel 
may be applied per foot of length. In other cases a cubic 
yard may be applied per foot. 

Roads may be graveled lightly by the surface method at 
a cost of from $200 to $500 per mile. Where the roads are 
constructed by the trench method, the cost usually varies 
from $1000 to $2000, but it may run as high as $3000 per 
mile. 

Maintenance of Gravel Roads. Gravel roads should be 
kept smooth and oval by the use of the road drag. The road 
drag is not needed as often on gravel as on earth roads, yet 
pockets and ruts should not be allowed to form. From time 
to time additional gravel should be added to the surface. 

When repairing gravel roads in this manner, it is 
customary to apply about two inches of gravel at a time, 
except at the places where the road has been destroyed, in 
which case it will be necessary to use more gravel. The 
length of time in which the gravel road may go without an 
application of additional material varies so much with the 
traffic, grade of materials used, and other conditions, that 
no attempt will be made to suggest an average period. 

QUESTIONS 

1. Under what conditions is the clay road at its best? 

2. How is a sand road improved? 

3. What principle is involved in the construction of the sand-clay 
road? 

4. How much does a sand-clay road cost? 

5. To what conditions is the gravel road adapted? 

6. What are the requisites of good road gravel? 



ROADS 159 

7. Why should road gravel vary in size? 

8. Why is it best not to use too large pebbles? 

9. What is common binding material? 

10. How much binder should be used? 

11. Why should a gravel road be thoroughly underdrained? 

12. Describe the surface method of constructing gravel roads. 

13. What thickness of gravel is usually applied? 

14. Describe the trench method of constructing gravel roads. 

15. How much do gravel roads cost? 

16. How are gravel roads maintained? 



CHAPTER XXVI 
STONE ROADS 

Stone roads include all roads on which broken stone is 
used as the principal surfacing material. Stone has been 
used in road construction from very early times, where 
first-class roads were desired. 

Telford Roads. Some broken stone roads are given the 
name of Telford, when they incorporate some features of 
road construction which were used by Mr. Thomas Telford, 
a famous English engineer. The distinguishing feature of 
the old Telford road was that the lower course or layer of 
stone was made of rather large flat stones laid in place by 
hand. At the present time any road which uses large pieces 
of material in the base or lower layer may be called a Tel- 
ford road. 

Macadam Road. Most stone roads which have been 
built in recent years follow the form of construction proposed 
by John Loudon McAdam, another famous English road 
engineer, who lived between 1756 and 1836. So general is 
the use of this construction that it has become customary to 
call all broken-stone roads macadam roads. 

Macadam roads are made of broken stone throughout. 
The stone is applied in three or more layers, and in the usual 
construction it is customary to place the larger fragments in 
the lower course. 

Road Stone. Not all kinds of stone can be used success- 
fully in the construction of stone roads. Good road stone 
must be hard so that it will not be crushed by the traffic 
which will come upon it. It must also be hard enough to 



ROADS 



161 



resist wear, which requires somewhat different character- 
istics from the ability to withstand pressure. Road stone 
should also, be tough, in order that it will not be shattered 
by the blows to which it will be subjected. It must also, in 
the usual macadam construction, furnish a dust which has 
a cementing or binding power. As the stone wears, a dust 
forms, which becomes lodged between the stone particles. 
This dust when wet forms a sort of cement which, upon 
hardening, holds the fragments of stone together, resembling 
in many respects cement or concrete. 

Testing Stone for Road Construction. Nearly every 
state maintains a highway commission which is equipped with 
apparatus for testing road stone for the various qualities 
mentioned. These tests are capable of determining fairly 
and accurately just what may be expected as to durability 
of a certain kind of stone when used in road construction. 
The construction of stone roads is so expensive that in no 
case should materials of doubtful value be used. 




Rolling the first cour.se of stone. 



162 



AGRICULTURAL ENGINEERING 



The Construction of Stone Roads. As usually con- 
structed, the stone surfacing in a country road is made from 
12 to 15 feet wide. The stone proper is usually applied in 
two layers, on top of which a third layer of stone dust or 
other binding material is used. The lower course is usually 
made from 23^ to 4 inches thick, and the upper courses 
from \]/2 to 2 inches thick. Thus the total thickness of the 
stone varies from 4 inches to 6 inches at the center of the 

road, and from 23^ inches 
to 4 inches at the outer 
edge. It is customary 
to apply more material 
in the center of the road, 
where the wear from 
traffic is the greatest, 
than at the outside. 

If automatic dump 
wagons are not used to 
spread the stone, it is 
generally recommended 
that it be applied with 
shovels. When stone is 
dumped in heaps, the 
larger fragments roll to 
the outside of the pile 
and the finer portion is 
left in the center. The stone should be applied in layers of 
uniform thickness, making proper allowance for the shrink- 
age due to rolling. The packing is done with a steam roller. 
Horse rollers are not made heavy enough for this purpose; 
the ten-ton traction roller is the size in general use. It is 
customary to begin the rolling at the outside and work 
toward the center. After the lower course is thoroughly 




Fig-. S5. Model of a water-bound macad- 
am road. A represents the prepared sub- 
grade. B represents the first course of 
coarse stone. C represents the second 
course of stone, and D the finishing layer 
of stone, chips or dust. (Bui. 36, Office of 
Public Roads, U. S. Dept. of Agr.) 



ROADS 163 

packed over the entire width oi the road, the upper courses 
may be applied. This consists of fragments of stone which 
vary in diameter from 1}4 to V/2 inches. After being 
spread in a manner similar to that described for the lower 
course, the layer of binding material, which usually con- 
sists of stone screenings and dust, is applied. This is usually 
about 1 inch in thickness and it is washed down into the 
crevices between the stone as much as possible by sprinkling. 
Rolling is continued until the water that is applied in 
sprinkling remains on the surface. No more binding 
material should be used than is necessary, and care should 
be used to leave the surface of the road as smooth and in as 
perfect condition as possible. After rolling and bringing 
the surface into proper condition, the embankments at the 
sides should be thoroughly rolled smooth so that there will 
not be any unevenness existing between the stone and the 
side ditches. 

Bituminous Macadam Roads. The construction which 
has just been described has been the standard method of 
stone road construction for many years, but owing to a 
change of traffic other forms of construction have come 
into use, and this construction is sometimes designated as 
"water-bound macadam roads." It has proved to be 
highly satisfactory for the main traveled country road, 
where first-class roads are desired and where the traffic 
is limited to horse-drawn vehicles. The automobile, how- 
ever, has introduced a new problem in connection with road 
construction. The automobile traveling at a high speed 
with its broad pneumatic tire sucks out from between the 
stone fragments the dust which forms the binding material, 
and causes the stone to loosen, or "ravel," as it is some- 
times described. So extensive has the motor traffic become 
in certain localities, that not only must steps be taken to 



164 



AGRICULTURAL ENGINEERING 



protect the macadam roads which are now in use, but 
another form of construction must be adopted for new 
roads. At the present time a rather large number of mate- 
rials are being used as binders experimentally. One class 
of these binders is known as bitumen, which includes 
not only the natural asphalt products but also similar 
material obtained from gas plants in the nature of tars. 
In addition to bitumen, various grades of oils are sometimes 
used to protect roads. Some of these are known as dust 
preventives. 

Method of Constructing Bituminous Macadam Roads. 
There are two general methods of constructing bituminous 

macadam roads. One is 
known as the penetration 
method, and the other 
the mixing method. In 
the penetration method, 
the foundation or sub- 
grade is prepared sub- 
stantially as for the 
water-bound macadam 
road, and the first or 
second layer of stone 
also applied in the same 
way. On the second, 
or upper, course or layer, 
bitumen is applied at 
various rates, averaging 
perhaps V/2 gallons per 
square yard. Following 
this a layer of stone 
chips is applied, and then another layer of bitumen at the 
rate of perhaps Y2 gallon per square yard. 




Fig. S6. Model of a bituminous macadam 
road made by the penetration method. A 
represents the prepared sub-grade. B rep- 
resents the first course of stone, and C the 
second course. D shows the first applica- 
tion of bitumin. E shows the application 
of a course of stone chips. F shows sec- 
ond application of bitumen. G shows the 
completed road with a layer of clean stone 
chips, lightly rolled. (Bui. 36, Office of 
Public Roads, U. S. Dept. of Agr.) 



ROADS 165 

In the mixing method, the second crust or layer of stone 
is mixed or covered with bitumen before spreading. This is 
also true of the upper layer of sand or chips, which is thor- 
oughly mixed with bitumen before applying to the surface. 
It is expected that roads of this type will largely replace the 
standard or water-bound type. 

Cost of Stone Roads. The cost of stone roads will vary 
largely with the cost of materials; this in turn being directly 
dependent upon their availability. The "cost in different 
parts of the United States varies from $1.20 to $1.50 per 
square yard, and from $4000 to $10,000 per mile. 

Maintenance. Macadam roads must be given constant 
attention or they will be rapidly destroyed. All ruts should 
be quickly filled with new material and not be allowed to 
become larger. After several years of wear, depending 
upon the durability of the materials used, it will be neces- 
sary to apply a new layer of materials. This is usually 
accomplished by loosening or scarifying the surface, leveling 
or rolling it until thoroughly compact, and then applying new 
material in a layer two or three inches thick, depending upon 
the condition of the road. This repair layer is applied in a 
way similar to the laying of the second course in the original 
construction. 

Brick Roads. In some localities where stone is very 
expensive or where good durable brick may be obtained 
cheaply, brick roads will be found to be the most practical. 
In the construction of a brick road, the subgrade or foun- 
dation is carefully prepared by grading and rolling, and the 
sides of the road are provided with concrete or wooden 
curbs, to hold the brick in place. On the subgrade a course 
of stone is laid and thoroughly rolled, or a coarse layer of 
concrete is spread, usually about 6 inches deep. On this 
course a layer of sand is spread and smoothed as a cushion 



166 AGRICULTURAL ENGINEERING 

on which the brick is laid. In order to allow for the expan- 
sion and contraction due to changes of temperature, an 
expansion joint must be left occasionally. 

Concrete Roads. Owing to a reduction in the cost of 
Portland cement, concrete is now used to a limited extent 
in the construction of roads. One objection to concrete 
roads is that they are slippery, but this may be overcome. 
The construction of concrete roads has not as yet become 
standardized. 

QUESTIONS 

1. What is a stone road? 

2. Describe the Telford form of construction for stone roads. 

3. Describe the construction of the macadam road. 

4. What are the requisites of stone for road construction? 

5. Why should road stone be tested? 

6. Describe the construction of water-bound stone roads. 

7. How much should a stone road be rolled at the finish? 

8. Describe two methods of constructing bituminous macadam 
roads. 

9. How much do macadam roads cost per mile? 

10. How should macadam roads be maintained? 

11. Where may brick roads be constructed advantageously? 

12. Describe the construction of brick roads. 

13. What is one objection to the concrete road? 



CHAPTER XXVII 



ROAD MACHINERY 

Classes of Road Machinery. Road machinery may be 
divided into two general classes, those used in building roads 
and those for the maintaining of roads. Although machines 
in the first class may be used in connection with the repairing 
of roads, there are a few machines which are used solely for 
this purpose. There is a rather wide variety of road 
machines, and it is not possible in this chapter to describe- 
even briefly all of the machines which might be considered. 
SCRAPERS, ROLLERS, ETC. 
Scoop Scrapers. One of the most simple machines used 
in connection with road construction is the scoop scraper, or 
"slip." This scraper is simply 
a large scoop arranged with a 
bail for drawing and handles for 
dumping. The size is usually 
indicated by the number of 
cubic feet of earth the scraper 
will hold, which varies from 3 
to 7. The cost of a scoop 
scraper varies from 6 to 10 dollars. The scoop scraper is 
used for moving earth short distances. 

Pole or Tongue Scraper. 
The pole or tongue scraper is 
used in leveling the road sur- 
face. The size is indicated by 
the width in inches, and the 
cost varies from 6 to 7 dollars. 




Scoop scraper or slip. 




Fig. 



Tongue scraper. 



168 



AGRICULTURAL ENGINEERING 




Buck scraper. 



Buck Scraper. The buck scraper is sometimes called 
the Fresno, and is used extensively in irrigated regions in 
preparing land for irrigation. It is capable of being adjusted 
to spread the earth in a layer of almost any thickness when 

dumped. These scrapers are 
made 3J^, 4, and 5 feet wide, 
and have capacities of 8, 10, 
and 12 cubic feet, respec- 
tively. 

The Wheel Scraper. The 
wheel scraper consists of a 
steel scoop on wheels and equipped with levers for raising 
and lowering and for dumping. It is used where the earth is 
to be moved some distance, 
100 feet or more. The size of 
this scraper is usually desig- 
nated by numbers 1, 2, and 
3, which have the capacities 
of 9, 12, and 16 cubic feet, 
respectively. There are sev- 
eral grades of construction 
to be obtained. If the haul, 
or distance the earth is to be 
moved, is great, the larger 
size should be used, even if 
an extra team or ''snap" be required to help load the scraper. 
The Scraping Grader. The scraping grader is the princi- 
pal machine used in the construction of earth roads. It con- 
sists usually of a four-wheeled truck, with a wide steel blade 
mounted underneath, which may be adjusted to almost any 
angle. The standard machine requires four or more horses 
to operate it successfully in average soil. A lighter or 
special machine is made which can be used for repair work, 




Fig. 90. Wheel scraper, clumped. 



ROADS 



169 



and is often used with two or four horses. In addition to the 
machines with four-wheeled trucks, there are quite a number 
of machines on the market in which attempts are made to 
simplify the construction, and also to reduce the cost. The 
standard scraping grader costs from $200 to $250 at the 
factory. In addition to the usual adjustments provided 
for setting the cutting blade to any angle with the direction 
of travel, for raising and lowering either end and giving it 




)1. • A scraping grader and a horse roller at work. 



any desired inclination forward or backward, the wheels 
of the machine are made to follow in the furrows of the blade, 
or may be adjusted at such an angle as to resist the side 
thrust due to using the blade at an angle with the direction 
of travel. The use of the scraping grader is quite simple, 
but much skill may be obtained by experience. In using a 
machine it is customary to plow a furrow at the side of the 



170 



AGRICULTURAL ENGINEERING 



road where the side ditch is to be located, using one corner 
of the blade. The earth from this furrow is then scraped to 
the center of the road and spread by the grader. 

Elevating Graders. The elevating grader is a compli- 
cated machine in many respects. It is provided with a four- 
wheel carriage and a plow that is operated at one side. An 
endless apron driven by power from the rear truck-wheels 
receives the earth from the plow and elevates and discharges 
it either in the center of the road or into wagons drawn 
beside the grader. These machines may be operated either 
by horses or by traction engines. The standard machine 
requires 12 horses, eight in front and four behind. This 




Fig. 92. An elevating: grader. 



machine will grade a new earth road in good soil at the rate 
of a quarter of a mile per day, where the width does not 
exceed thirty feet and where a crown of twelve inches at 
the center is made. Elevating graders vary somewhat in 
size and weight. 

Horse Rollers. Horse rollers for road construction con- 
sist essentially of a large cast-iron drum with a frame and 
tongue for drawing. They are usually made 4 to 6 feet wide 



ROADS 171 

and weigh from 3 to 6 tons. To overcome the difficulty of 
turning the roller about, a tongue with a wheel truck is 
attached to a yoke which is pivoted directly over the center 
of the roller drum, and which may be unlatched from one 
side and turned about to the opposite side and latched, 
enabling the drum to be drawn in the reverse direction with- 
out turning. Rollers made of cast iron cost about $100 per 
ton of weight. Cheaper rollers are made by building up 
the hollow drum of cast iron or steel plate, and filling with 
water or concrete. In the construction of stone roads it is 
highly essential that a heavy roller be used, and for this 
reason the horse roller is seldom used. 

Power Rollers. The steam roller is of two types, one is 
known as the three-wheel roller and the other as the tandem 
roller. The three-wheel roller resembles the traction engine, 
in which the guide wheels are replaced with a rolling drum 
and the drive wheels have smooth treads. Gasoline and oil 
engines are being substituted for steam power for rollers 
to some extent. Many traction engines are made so as to be 
easily equipped in this way. The weight of these rollers 
varies from 10 to 20 tons and the pressure under the drivers 
will vary from 450 to 650 pounds per inch of width. 

Tandem rollers, sometimes called asphalt rollers, con- 
sist of two rolling drums at the ends of a frame. Most of the 
weight is applied to one of these drums, which is driven by 
power from a steam or a gasoline engine, and the other is 
used for guiding. This type of roller tends to leave the sur- 
face smoother than the three-wheel type, but cannot be 
handled quite as conveniently over country roads. Although 
it can be used for drawing other machines it is not used so 
extensively in this connection as the three-wheel type. It 
cannot be provided with spikes for loosening old road sur- 
faces preparatory to resurfacing. 



172 



AGRICULTURAL ENGINEERING 



Rock Crushers. One of the essential machines in con- 
nection with the building of a stone road is the rock crusher 
for reducing stones to fragments of the proper size. Usually 
these crushers are located at the quarry, and the stone is 
shipped ready for application to the road. 




Stone crushing plant, 
dump wagon are 



A thp't-w heeled steam roller and 
shown in the foreground. 



Other Machinery. The equipment necessary for build- 
ing stone roads includes several other machines. Among 
these may be mentioned screens for grading the stone, dump 
wagons for hauling and spreading the stone, and sprinklers 
for applying water or binding material in the form of a 
liquid. When old roads are to be repaired, plows or scari- 
fiers, which are heavy tools with cultivator-shaped teeth for 
breaking up the surface, are necessary. 



ROADS 173 

MACHINES FOR MAINTAINING ROADS 

Road Drags. The principal machine for maintaining 
roads of all kinds is the road drag. As devised by Mr. D. 
Ward King this consists of two planks or halves of a split 
log, about 8 feet long, and held about 30 inches apart with 
braces. These planks are so placed that one will follow 
the other when drawn at an angle of 45 degrees with the 
direction of travel. The front plank is usually shod with a 
steel blade for about one-half its length, which resists the 




^3' fro/t plate 

Fig. 94. Road drags made of plank and split log. 

wear and enables the drag to have more effect upon the sur- 
face. Two chains are provided, one from each end of the 
drag, which are of such length as to give the drag the desired 
inclination with the direction of travel. 

It has been found that the drag works best with the longer 
chain passed over the plank, and the shorter chain attached 
near the middle of the short plank close to one end. There 
are many other types of drag to be found in use. One is 
known as the V drag, which is designed to cover the entire 
width of the road surface at a time. There are also several 
types of road drags made of angles or bars of steel in place of 
the planks of the King drag. 



174 AGRICULTURAL ENGINEERING 

QUESTIONS 

1. For what may the scoop scraper, or slip, be used? 

2. What are the special uses of the tongue and buck scrapers? 

3. Describe the construction of the wheel scrapers. 

4. Why is it economical to use large sizes where the haul is long? 

5. Describe the work of the scraping grader. ' 

6. Describe the construction of the elevating grader. 

7. What is the usual weight of horse rollers? 

8. Describe two types of steam rollers. 

9. What are some of the machines required for the building of 
stone roads not mentioned above? 

10. Describe the construction of a road drag of plank or split logs. 



CHAPTER XXVIII 
CULVERTS AND BRIDGES 

Importance of Culverts and Bridges. A large proportion 
of the cost of maintaining the highways of the country is 
used in the construction of culverts and bridges. Not only 
is it desirable that the money thus expended be used in such 
a way as to secure the best results, but faulty construction 
should be guarded against on account of the risk of life to 
those who must pass over them with heavy loads. To 
secure economy it is necessary that bridges and culverts be 
intelligently and economically designed, and that they be 
made of durable and permanent material. Recent changes 
in road traffic demand that there shall be advancement in 
the designing and constructing of culverts and bridges, in 
order that the heavier loads which bridges are now called 
upon to bear shall be carried without risk of failure. 

Design of Culverts and Bridges. The designing of cul- 
verts and bridges should be placed in the hands of a skilled 
engineer, who will be able to proportion the structure 
properly. The practice in certain localities of making appro- 
priations of public funds for bridges without first securing 
from one who has had experience, an estimate of the cost of a 
bridge to fill the requirements of the conditions to be met, 
may be justly criticised. 

Size. The first feature in the consideration of a culvert 
is the determination of the size required. Highway engineers 
have reported that culverts are often not properly propor- 
tioned to the needs to be met, being either too large or too 
small. The area of a cross section of a culvert or bridge 



176 



AGRICULTURAL ENGINEERING 



should vary with the amount of water which must pass 
through it. Some engineers use Kutter's formula, given 
in the chapter on land drainage. To determine the required 
area of the cross section of a culvert, a more simple formula 




Fig. 95. Making a concrete culvert. 



has been proposed by Professor A. N. Talbot, of the Uni- 
versity of Illinois. Professor Talbot states that the formula 
is to be used as a guide to judgment. It is stated as follows: 



ROADS 



177 



The area of waterway in square feet should equal 



C X 



4, 

V 



(drainage area in acres) 3 



in which C is a coefficient and will vary from /i5 to 1, the larger 
value being used where the slopes are steep and the ground is 
broken. The 4th root of the quantity under the radical may 
be obtained by extracting the square root of the square root. 

Foundation. Many bridges fall because they are not 
placed upon a proper foundation. Great care should be used 
to see that solid earth which will not be undermined by water 
is available for the smaller bridges. For larger bridges the 
foundation should be placed on solid rock, if possible; and 
where this can not be done, piling and other methods of 
providing large surface for the foundation should be used. 

Concrete Culverts and Bridges. Perhaps there is no 
purpose to which concrete made of Portland cement can be 
put to better use than in the construction of culverts and 



LOAOtNO 
UL L ■ IQ0L&3 p£f Sffr 
CLL ZOt 
O L S~00 L, 




item IA-AAW 


Faor m Lcnytf-, 






l-ZXrS\B3 £ 
















Carr 8an,-s-10\ CO Bars 








r ofa , Co'rBws\ 'S6FT ■■ ,4, Lb, 



Fig. 96. Plans and table of materials for reinforced concrete culvert. 



178 



AGRICULTURAL ENGINEERING 



bridges. Stone and brick make desirable culverts, but the 
convenience of handling and reinforcing concrete with steel 
makes it very useful for culvert and bridge construction. 
Vitrified Pipe and Steel Pipe Culverts. Vitrified clay 
pipes or sewer pipes are used extensively for small culverts, 
and are quite satisfactory when covered with a sufficient 

amount of earth. It 
is desirable, however, 
that the ends be pro- 
tected with wing walls 
made of masonry. 
Steel or iron pipes are 
used to a considerable 
extent; but owing to 
the thinness of the 
metal in most cases, 
they are regarded as 
of questionable merit. 
Castiron pipes are 
regarded as quite 
satisfactory, but are 
expensive. 

The Work of State 
Highway Commis- 
sions. The majority of states now have a highway com- 
mission or a highway engineer, whose function is to furnish 
standard plans and specifications for culverts and bridges. It 
is advised that these plans and specifications should be used 
in all cases. Besides representing the most improved design, 
they enable the work to be let by contract in a highly satis- 
factory way. All features of the construction will be clearly 
defined as to quantity and quality in the plans and specifi- 
cations furnished by these officers. 




Concrete culvert after the plan of 
Fig. SS. 



ROADS 



179 



Large Bridges. All large bridges should be designed and 
their construction supervised by a skilled engineer. In the 




Fig. 98. A concrete bridge which failed on account of the foundation. 

majority of states the state highway commission is in a posi- 
tion to furnish such an engineer. 



QUESTIONS 

1. Why should culvert and bridge construction receive careful 
consideration? 

2. What should be considered in selecting a culvert or bridge? 

3. What should govern the size of the culvert? 

4. Why is it important to have good bridge foundations? 

5. Why is concrete a good material for culverts and bridges? 

6. What are the merits of metal culverts? 

7. What is the work of the State Highway Commission? 

REFERENCE TEXTS 

Roads and Pavements, by I. O. Baker. 

Highway Construction, by Austin T. Byrne. 

A Text -book on Roads and Pavements, by Frederick P. Spaulding. 

Bulletins of the Office of Public Road^, U. S. Depart, of Agric. 



PART FIVE— FARM MACHINERY 



CHAPTER XXIX 
FARM MACHINERY AND AGRICULTURE 

Introduction of Farm Machinery. Farming, or the culti- 
vation of the soil to obtain a sustenance, was a recognized 
occupation even before the time history was first written. 
For ages, however, there was little development in farm 
machinery. Until the beginning of the last century nearly 
all of the work of the farm was performed by the aid of crude 
hand tools. The number of horse- or animal-drawn imple- 
ments or machines that had been developed were few. 

Although hand tools were used almost exclusively for 
thousands of years, when the application of power other than 
man power to the work of the farm began, the development of 
machinery was very rapid. In the Twelfth Census Report it 
is stated, "The year 1850 practically marks the close of the 
period in which the only farm implements and machinery 
other than the wagon, cart, and the cotton gin, were those 
which, for want of better designation, might be called imple- 
ments of hand production." In the early part of the nine- 
teenth century the grain was cut with the sickle or cradle 
and bound by hand. It was threshed by beating with the 
flail or by the treacling of animals. The plow was a crude 
affair, usually home-made and shod with iron by the village 
blacksmith, and the principal tool for cultivation was the 
hoe. A cast-iron plow was first made by Charles Newbold, 
of New Jersey, sometime between 1790 and 1796, and John 



FARM MACHINERY 181 

Deere made his first steel plow in 1833. Patents on the 
reaper were granted to Obed Hussey in 1833 and to Cyrus 
W. McCormick in 1834. The two-horse cultivator was first 
used about 1861. The first patent on a drill granted to an 
American was in 1799, but the force feed for a drill was not 
patented until 1851. The first patent on a corn planter 
came in 1839. 

These machines did not come into general use until many 
years after the date of the first patents. The old men of 
today can remember the hand methods which prevailed 
throughout the country during their boyhood and young 
manhood. The opening of large areas of rich agricultural 
land to settlement in the United 
States during the middle of the 
century, followed by the scarcity 
of workers caused by the Civil 
War, were no doubt the im- 
portant influences in bringing 

, • i • • r Fig - 90 - The sickle and tlle 

abOUt a rapid introduction Of cradle, hand tools for harvest- 
farm machinery. 

The influence of the introduction of farm machinery on 
agriculture has been stupendous and far-reaching. Some of 
the direct effects produced will now be set forth. 

Change in Farm Labor. When hand methods prevailed, 
the labor of the farm was performed largely by slaves or the 
cheapest form of labor. From the beginning, the cultiva- 
tion of the soil has been synonomous with deadening toil 
and drudgery. The introduction of farm machinery has 
changed this entirely, a fact which is emphasized by the com- 
parison of the harvesting of grain with a modern self -binding 
harvester with the old method of cutting with the sickle or 
cradle and binding by hand; or the threshing of grain with 
a modern threshing machine equipped with self-feeder, 




182 AGRICULTURAL ENGINEERING 

weigher, and wind stacker compared with the threshing of 
grain with a flail. 

A poet once wrote of the agricultural laborer as the "man 
with the hoe, stolid and stunned — a brother to the ox." 
Contrast this condition with that of the operator of a modern 
machine like a gang plow, a harvester, or a two-row culti- 
vator, where no effort is required beyond the direction of the 
energy of the horses and the adjusting of the machine. 
J. R. Dodge, in the Report of the Industrial Commission, 
1901, wrote, "As to the influence of machinery on farm 
labor, all intelligent expert observation declares it benefi- 
cial. It has relieved the laborer of much drudgery; made his 
work easier and his hours of service shorter; stimulated his 
mental faculties ; given an equilibrium of effort to mind and 
body ; and made the laborer a more efficient worker, a broader 
man, and a better citizen." It is doubtful if farming would 
appeal at all to the young men of today if there had not been 
a change from hand methods to machine methods. 

Length of Working Day. The working day has been 
materially shortened since the introduction of labor-saving 
machinery. The capacity of the worker was so limited with 
hand methods that it was necessary to work to the limit of 
endurance when crops demanded it. 

Increase in Wages. There has been a very marked 
increase in wages with the introduction of farm machinery; 
and although this is true of all occupations, farm machinery 
has undoubtedly been a factor in bringing about the increase. 
A farm worker can earn more by working with a machine 
than by hand; however, a complicated machine requires 
greater skill for its successful operation. It was thought 
by many at the time machinery was being generally intro- 
duced that wages would be decreased, owing to the fact that 
some workers would be displaced with machines. In the 



FARM MACHINERY 183 

United States, in 1849, the average wages of a farm worker 
did not exceed $120 a year. In countries where machinery 
is used little at the present time, wages are very low. 

Labor of Women in Fields. When hand methods pre- 
vailed, the labor of women was required in the fields to care 
for the crop during the seasons when they required urgent 
attention. Now the services of women are seldom required 
in the field, and in addition many machines have been 
devised to aid her in the house work. Again, much of the 
work formerly required of her in the home, like spinning, 
weaving, garment making, soap making, and candle making 
have been transferred to the factory, where machinery may 
be economically used in the work. 

Percentage of Population on Farms. The percentage of 
the total population living on farms in the United States has 
decreased continually since 1800. At that time 97 per cent 
of the people lived on farms; in 1849 the percentage had 
decreased to 90 per cent, and in 1899 only 35.7 per cent of the 
people lived on farms. 

Increase in Production. Notwithstanding the decrease 
in the farm population in this country, the production of 
agricultural products per capita has increased. In 1800, 
5.50 bushels of wheat were produced per capita; in 1849, 
4.43 bushels; in 1880, 9.16 bushels; in 1890, 7.48 bushels; 
and in 1900, 8.66 bushels per capita. The production of 
corn per capita increased from 25.53 bushels in 1850 to 34.94 
bushels in 1900. 

Cost of Production. The cost of producing farm crops 
has been materially lowered, although the cost of labor has 
increased many fold. It is stated by one authority that the 
average cost of producing farm crops was reduced 50 per 
cent from 1850 to 1895. This reduction of cost is largely 
due to a reduction in the time required in production. In 



184 AGRICULTURAL ENGINEERING 

the thirteenth annual report of the Department of Labor it 
is stated that the amount of labor required to produce a 
bushel of wheat by hand methods was 3 hours and 3 minutes, 
and by machine methods this has been reduced to ten min- 
utes. In the 1899 Yearbook of the Department of Agricul- 
ture it is reported that the average time of labor required to 
cut and cure a ton of hay has been reduced from 11 hours to 
1 hour and 39 minutes. 

Quality of Products. The quality of farm products has 
been materially influenced by the introduction of farm 
machinery which enables the farmer to harvest his crop at 
the best time. For instance, when hand methods prevailed 
it was customary to begin the harvesting of small grain 
before it was properly ripened, and the harvesting was con- 
tinued past the time the grain was in the best condition, 
resulting in shrunken and damaged grain. The crops are 
generally cleaner and more uniform now than under the 
methods prevailing three quarters of a century ago. It 
would be difficult now to induce people to eat bread made 
from wheat threshed by the treading of animals. 

Income of Farm Workers. A study of the Census 
report of the income of farm workers in the different states 
and the average investment in farm machinery indicates 
that the income varies almost directly with the amount of 
machinery. 1 The following table contains only the extreme 
cases given in the report. 

G. F. Warren and K. C. Livermore, of Cornell University, 
in reporting an agricultural survey made in Tompkins 
County, New York State, say, "In each of the groups [refer- 
ring to size of farms] the farmer's labor income is almost the 
same as the value of his machinery." These observations 



IS. A. Knapp, of the United States Department of Agriculture, has reported 
this data from the census report, in Circular 21, Bureau of Plant Industry. 



FARM MACHINERY 
Influence of farm machinery on income. 



185 



State 


Annual income of each 
worker 


Value of ma- 
chinery and im- 
plements for 
each farm 


Florida 

Alabama 

Iowa 


$119.72 
143.98 
611.11 

755.62 


$ 30.43 

23.40 

196 55 


North Dakota 


238 84 







are sufficient to indicate clearly that farm machinery is an 
important factor in modern farming operations and that an 
agricultural student who intends to make the farm the object 
of his life work will do well to give a careful study of the 
subject of machinery. 

QUESTIONS 

1. Explain some of the causes which brought about a rapid de- 
velopment of agricultural machinery in America. 

2. What were the hand tools used in harvesting and cultivation? 

3. What effect has the use of machinery had on farm labor? 

4. Has the length of the working day changed since the introduc- 
tion of farm machinery? Explain. 

5. How have wages changed since the time of hand production? 

6. Show how machinery has changed the work of women. 

7. Explain how production of some of the principal crops per capita 
in the United States has changed, and also explain the changes in the 
percentage of the population living on farms. 

8. How has the cost of production changed with the introduction 
of machinery? 

9. What effect has machinery upon the quality of products? 

10. What is the ratio between the amount invested in farm ma- 
chinery in the various states and the average income of the farm 
workers? 

Note: The student should study the development of farm 
machinery by consulting the older residents in the community in regard 
to the methods in vogue during their lifetime. A study should also 
be made of the cost of doing work by different existing methods. 



CHAPTER XXX 
DEFINITIONS AND PRINCIPLES 

A Tool. A tool is an instrument such as a hammer, fork, 
or spade used in performing manual operations. Tools so 
defined will not be discussed in this text. The term may be 
used, perhaps incorrectly, to designate a machine or an imple- 
ment. Machines for making hay, for instance, are some- 
times called hay tools. 

Implements. The term implement is applied to both 
tools and machines. A dealer in these wares is generally 
known as an implement dealer. 

Machines. A machine is any device consisting of two 
or more parts arranged to modify forces and motions, to 
produce a desired effect or do some useful work. Machines 
require energy from an outside source to drive or operate 
them, and of this energy a part is required to drive the 
machine itself and a part is required to do the useful work. 
As will be explained later this energy is generally designated 
as work. The ratio between the work put to any useful end 
and the total amount of work given to the machine is known 
as the efficiency of a machine. For instance, suppose that 
a certain machine, like a pump, requires one horsepower of 
energy to operate it. Suppose that of this amount, one- 
half horsepower is used in the actual lifting of the water 
and the remainder is used in overcoming the friction in the 
pump. Then the efficiency of the pump is 50 per cent. 

Elements of Machines. All machines, regardless of their 
intricacy, may be reduced to the elements of machines, or 
the simple machines, as they are called. These comprise 



FARM MACHINERY 187 

the fundamental devices for modifying forces and motions. 
They are six in number, and are the lever, the wheel and axle, 
the inclined plane, the screw, +he wedge, and the pulley. 

Essentials of a Machine. Any machine to be satisfac- 
tory must fulfil at least four requirements. First, it must do 
the work required of it satisfactorily; for instance, a har- 
vester must cut the standing grain and bind it into bundles 
with never-failing accuracy. Second, the machine must do 
its work efficiently; that is, it must require little power to 
drive it, as in the case of horse-drawn machines, where the 
draft must be low. Third, the parts of the machine must be 
strong enough to resist breakage. Fourth, the machine 
must be so designed as to be durable, or able to resist wear; 
such parts that are subject to wear should be capable of 
adjustment or replacement. 

The first two of these requirements demand proper con- 
struction on the part of the machine and skillful adjustment 
and management on the part of the operator. The number 
of farm machines now manufactured is very large, and in 
most cases there are several types and sizes of a machine for 
each kind of work. Each machine will do its best work and 
render the best service when used under the conditions for 
which it is made to work. The part of this text devoted to 
farm machinery is planned, in the main, to give instruc- 
tion in the selection, adjustment,* and operation of the various 
farm machines required in general farm practice. In addi- 
tion, there will be a discussion of the principles involved in 
the strength and durability of a machine. 

Friction. As a machine operates, there must be at cer- 
tain points a sliding of one surface over another. It matters 
not how carefully the surfaces may be prepared there is 
always some resistance to the sliding, which resistance is 
known as friction. The magnitude of this resistance in 



188 AGRICULTURAL ENGINEERING 

friction varies much with conditions and it is desirable in 
most instances to keep it as small as possible, as it is a waste 
of energy or power and lowers the efficiency of the machine. 
There are instances where friction is highly essential, as in 
the case of the transmission of power by means of a belt, or 
the use of friction in the friction clutch in engaging a part at 
rest with a revolving part. The shoes of the clutch slip 
when first engaged, allowing the parts at rest to attain speed 
slowly, thus relieving the machine of severe shocks, but 
finally they furnish enough resistance to slipping to transmit 
the full power of the machine. The ratio between the force 
holding the two surfaces together and the force necessary to 
slip one surface over the other is called the coefficient of 
friction. Thus if a body weighing 10 pounds requires a hori- 
zontal force of 1 pound to move it over a level surface, then 
the coefficient of friction equals .1. In most instances it is 
desirable to keep the coefficient of friction as low as possible, 
which is done by making the sliding parts of the machine of 
materials which give a low coefficient of friction, and by 
applying a lubricant between the surfaces. 

When two surfaces in contact are at rest for a time they 
seem to interlock, so that a greater force is required to cause 
them to start to slide over each other than to continue the 
movement after sliding begins. The friction of rest is there- 
fore greater than the friction of motion. 

Rolling Friction. When a body with a circular cross 
section is rolled over, a plane surface, some resistance is 
offered, but not as much as in the case of sliding. This 
resistance is due to a compression or indentation of the sur- 
faces in immediate contact ; hence rolling friction is less with 
hard bodies. Since rolling friction is so much less than 
sliding friction, rollers are often inserted between two sur- 
faces which would otherwise slide over each other. 



FARM MACHINERY 189 

Lubrication. To reduce friction between two sliding sur- 
faces and to reduce the wear and heating, it is common 
practice to apply some substance which will adhere to each 
of the surfaces in a thin layer, smoothing them, and pre- 
venting them from coming in such close contact. Such a 
substance is called a lubricant. The friction really takes 
place between two surfaces of the lubricant. 

Oils and greases are generally used as lubricants. 
Graphite, which is carbon in a very finely divided state, is 
often used in connection with oils, and has the property of 
smoothing the surfaces. Mica finely divided is used in the 
same way in axle grease. 

Choice of a Lubricant. It is desirable that lubricating 
oil be as light and thin as possible, and still heavy enough, 
or having enough "body," to prevent being squeezed out 
from the surfaces in contact. Heavy oils and grease, being 
more viscous, give a higher coefficient of friction, and are 
not adapted to surfaces moving over each other at high speed. 
Thus light oils are chosen for machines running at high 
speeds and where the pressures between the lubricated sur- 
faces is not great, as in the case of cream separators. Heavy 
oils and greases are used where the pressure is great and the 
motion slow, as on axles. Manufacturers provide special 
lubricants for nearly every purpose, and it is well that special 
oils be used as far as possible. Gas engine cylinder oil is so 
made as to stand high temperature; and although other oils 
may be as good a lubricant at normal temperature, they 
would be worthless at the temperatures prevailing in the gas 
engine cylinder. 

Table of Coefficient of Friction. The following table* 
indicates in a general way the influence of surfaces of different 
materials and different lubricants upon friction. 

*From "Bearings and Their Lubrication," by L. P. Alford. 



190 



AGRICULTURAL ENGINEERING 
Coefficient of friction of various surfaces. 



Surface in contact 


Condition of the 
surface 


Mutual arrange- 
ment of the fibers 


Coefficient 
of friction 


Oak on oak 
Oak on oak 


Dry 

Oily 

Coated with tallow 

Coated with tallow 

Dry 

Oily 

Coated with lard 

Coated with lard 


Perpendicular 
Parallel 


0.336 
0.108 
0.055 






0.078 






0.152 






0.144 


Cast iron on wrought iron 




0.053 




0.070 


Balls on hardened steel 




0.002* 








0.0099* 










Fig. 100. A plain 
bearing. 



*Approximate values; coefficient of friction varies with speed and load. 

Bearings. The bearings are the parts of a machine which 
contain the rotating parts. When the bearings are a sepa- 
rable part of the machine they are often called boxes. 
Bearing should be designed, first, from 
material which will give a low coefficient 
of friction; second, so that the surfaces 
may be thoroughly lubricated; third, from 
materials that will resist wear or which 
can be easily replaced; and fourth, in most cases they 
should be adjustable for wear. 

A bearing which is made in one piece and is separable 
from the rest of the machine is styled a solid box. A bearing 
supported on pivots or in a socket 
which will permit its axis to be moved 
easily is called a self-aligning bearing. 
The rotating part which comes in 
contact with a bearing is usually desig- 
nated as the journal. The journal is 
generally made of a harder material 
than the bearing. Thus the journal 
is usually made of steel and the bearing of brass, bronze, 




Fig. 101. A self-align- 
ing bearing. 



FARM MACHINERY 



191 



or babbitt. When made of different materials there is less 
tendency for the surface to become rough and abraded. 

Roller and Ball Bearings. Roller and 
ball bearings substitute rolling friction for 
sliding friction. Such bearings are usually 
much more expensive than plain bearings, 
but in many places the extra expense is 
justified. Roller bearings furnish a very 
satisfactory means of holding a supply of the lubricant and 
prevent binding and heating, due largely to misalignment. 




102. A ball 
bearing. 




Fig. 103. A roller bearing for wagons. The hub of the wheel fits over 
the rollers shown. 



Ring Oiling Bearings. A ring oiling bearing has a 
reservoir of oil underneath the shaft, or journal, into which a 
ring resting on the upper side of the shaft is allowed to dip, 
and as the shaft rotates the oil is carried up onto the shaft, 

where it spreads out to 
each side, thoroughly lu- 
bricating the bearing. 
Such a bearing is very 
desirable for a machine in 
continuous service. 
Inclosed Wheel Boxes. It is customary on the best 
machines that are to be subjected to much dust, to enclose 
the outer end of the wheel boxes and provide a collar at the 
inside end of such a construction as to practically exclude all 
dust. The lubricant is usually "hard oil" or heavy grease, 




oiling bearing 



192 



AGRICULTURAL ENGINEERING 




Fig. 



105. An inclosed 
wheel box. 



supplied by screwing off the inclosed end of the wheel box. 
The grease thus works toward the inside end of the box and 
still further assists in excluding the 
dirt and grit. 

Oil and Grease Cups. The gen- 
eral character of a machine can often 
be determined by the kind of oil and 
grease cups used on the machine. 
No machine should be purchased 
which does not have an adequate provision for lubricating 
all bearings. 

Babbitting Boxes. Babbit metal is a mixture of several 
metals having a rather low melting point, and is used to line 
boxes. Genuine babbitt metal is mixed in 
the proportion of 1 part of copper, 2 parts of 
antimony, and from 6 to 24 parts of tin; but 
the name is applied to many combinations of 
metals used as a lining for boxes. Besides 
furnishing a very satisfactory metal for a 
bearing, babbitt metal can be quite easily 
replaced. 

In preparing to babbitt a box it is neces- 
sary to be provided with a melting ladle and 
a fire, preferably a forge fire, to heat it. The 
worn babbitt which is to be replaced is 
carefully removed with a cold chisel and the 

box freed from grease and moist- 
ure. The shaft is carefully blocked 
into position, leveled and centered, 
and the ends of the box closed by 
cardboard collars fitting around 
the shaft and held in place with 




Fig. 106. A sight 
feed oil cup. 




grease cup 
hard oil. 



putty or stiff clay mud. 



FARM MACHINERY 193 

If the box is solid, a piece of writing paper is wrapped 
around the shaft, or journal, to give clearance or to prevent 
the box from being too light. This paper is held in place by 
a cord which burns up and leaves a useful oil groove. If the 
box be split, or made in two halves, cardboard liners should 
be inserted between the halves, fitting against the shaft to 
divide the babbitt. Notches may be cut in these liners to 
let the molten metal flow from one side to the other. When 
hardened, the metal in these notches may be broken by driv- 
ing a cold chisel between the halves of the box. 

It is usually best that the boxes be warmed before pour- 
ing the metal, and the metal should be hot, to insure that it 
will fill every part of the box. The metal is usually poured in 
through the oil hole. When the metal has hardened and the 
box removed, the oil hole should be drilled out, and, if the box 
is a large one, oil grooves should be cut to lead the oil away 
from the oil hole, to insure that all parts of the bearing will 
be covered with oil. Often an old machine, when babbitted, 
will run like a new one, the rattle and vibration due to the lost 
motion in the bearings being overcome. 

Adjustment of the Bearings. The proper adjustment of 
a bearing requires much skill. If the bearing be too tight it 
will heat, and if too loose it will knock and also heat. A good 
rule to follow is to screw the top of the box down upon paper, 
cardboard, or metal strips (called liners) between the halves 
of the box until the box is rigid, selecting liners of such thick- 
ness as will make the box fit the shaft as tightly as possible, 
yet offering no resistance to the free turning of the shaft. 

QUESTIONS 

1. Define a tool. An implement. A machine. 

2. What is meant by the efficiency of a machine? 

3. Name the elements of a machine. 



194 AGRICULTURAL ENGINEERING 

4. What are the three essentials of a practical machine? 

5. Why is the selection of a machine important? 

6. What is friction? 

7. Define the coefficient of friction. 

8. Wliat are some of the conditions that modify the coefficient of 
friction? 

9. What would be the draft on ice of a sled weighing 4000 pounds 
if the coefficient of friction between the runners and the ice is 0.025? 

10. Mention several instances where friction is especially useful. 

11. Why is friction of rest greater than friction of motion? 

12. What is the cause of rolling friction? 

13. What are the purposes of lubrication? 

14. What kind of lubricant should be used on a machine like a 
harvester? 

15. Of what value is graphite as a lubricant? 

16. What should be taken into account in the design of a bearing? 

17. Why should the material used for the bearing be different from 
that of the journal? 

18. When are roller and ball bearings best? 

19. Explain the process of babbitting a box. 

20. How should a bearing be adjusted? 



CHAPTER XXXI 
MATERIALS 

Importance of Quality. The durability of a machine 
depends largely upon the quality and character of the mate- 
rials used in the construction of it. It is obvious that a 
knowledge of the properties of these materials will be use- 
ful to those who have to do with the selection and manage- 
ment of machinery. 

Wood. Twenty-five to forty years ago the framework 
of farm machinery was made largely of wood. At that 
time wood stock of the first quality and of the most desir- 
able varieties could be obtained cheaply. The increase in 
the cost of wood, due to its scarcity, and the decreasing cost 
of manufacturing iron and steel has lead to a more extended 
use of metal. The wood used in the construction of farm 
machinery, since it must undergo rather severe service, 
should be of selected quality. Carefully selected, well-sea- 
soned heartwood is the only practical kind to use. 

Wood is influenced more or less by moisture, and for 
that reason should be carefully protected by paint. A 
combination of iron and wood parts is apt to give trouble 
by becoming loose, due to the shrinking of the wood. Parts 
subject to much vibration, like the pitman of a mower, 
can best be made of wood. Excessive vibration and shocks 
tend to cause steel to crystallize. 

Some of the more common varieties of woods and forms 
of metal used in the construction of farm machinery will 
now be discussed. 



196 AGRICULTURAL ENGINEERING 

Hickory is a very dense, heavy wood of great strength 
and elasticity. It is the hardest and toughest wood used in 
the construction of farm machinery and vehicles. It is 
preferred to all others for axles, buggy spokes, shafts, etc. 

Oak is a hard wood but not so tough as hickory. It is 
used to some extent for wagon axles, doubletrees, and gen- 
erally for parts where stiffness is required. The best kind 
of oak for these purposes is white oak. Red oak or black 
oak is not so hard and stiff. 

Ash is hard, tough, and elastic, and for that reason is 
quite generally used for handles of hand tools, such as forks. 
It is a white, coarse-grained wood 

Maple. Hard or "rock maple" is a hard, fine-grained 
wood which is quite stiff, and is being used to some 
extent as a substitute for hickory. 

Beech is a hard, strong and tough wood of very close 
grain and will take a very high polish. 

Birch. Black birch is a dark, close-grained, tough 
wood. It is used to some extent for wagon hubs, on account 
of its resistance to checking. 

Poplar is a wood which may be obtained very free from 
knots. It is light yellowish in color, has a close grain, and 
is very tough compared with the lighter woods. It is the 
standard material for wagon boxes and buggy panels. Cot- 
ton wood, a very close relativQ-of-the poplar, is used to some 
extent as a substitute. 

Pine. There are many varieties of pine to be had. 
Long leaf yellow pine has a decided grain and is quite stiff. 
It is used largely in the construction of field hay tools and 
for similar purposes. White pine is used where soft, light 
wood is desired. 

Cast Iron. The cheapest metal used in the construc- 
tion of farm machinery is cast iron. It is crystalline in 



FARM MACHINERY 197 

structure and it can not be forged or welded. It is 
shaped by machine tools, by drilling, turning, or planing. 
It is used for the heavy parts of machines, for gears or 
where irregular shapes are desired, which may be obtained 
by casting molten iron. Cast iron may be usually de- 
tected by the lines and roughness given to it by the sand 
mold in which it is cast. It is easily detected upon breaking 
by the crystalline structure. 

Chilled Cast Iron. Where a particularly hard surface 
is desired, a special kind of cast iron is used, obtained by 
making a part of the mold of heavy iron, which chills the 
molten metal as soon as it comes in contact with it and 
makes it very hard. 

Malleable iron is cast iron which has been annealed 
and relieved of a part of its carbon by heating in furnaces 
for several days. Malleable iron is soft, tough, and some- 
what ductile, and is used to replace cast iron where these 
characteristics are required. When broken, malleable iron 
shows a soft malleable surface and a crystalline center. 

Cast Steel. Cast steel is, in brief, cast iron less a part of 
the carbon. It is less brittle than cast iron, and is used for 
gears and other parts subject to severe stresses. 

Mild and Bessemer Steel. Most of the material now 
used in the construction of farm machinery is mild or Besse- 
mer steel, which is made by a special process. It is a very 
tough metal whose stiffness can be regulated by the manu- 
facturer by varying the carbon content. It can be easily 
forged, but does not weld as readily in an open fire as 
wrought iron. 

Wrought Iron. Wrought iron is nearly pure iron. It 
is very ductile and can be easily forged or welded. The 
purest and best grade of wrought iron is known as Norway 
or Swedish iron. 



198 AGRICULTURAL ENGINEERING 

Soft-Center Steel. The ability of carbon steel to be 
hardened depends largely upon the percentage of carbon 
it contains. When hardened, it will take a most excellent 
polish, as is desired for plows, but hardened steel is brittle 
and will not stand shocks. To overcome this shortcoming, 
soft-center steel has been invented, which consists of a layer 
of soft steel between two layers of high-carbon steel. This 
soft, low-carbon steel lends toughness to the whole plate. 
Soft-center steel is quite generally used at the present time 
in the manufacture of shovels and plows. 

Tool Steel. Tool steel contains a rather high percentage 
(0.6 to 1) of carbon, is capable of being hardened and tem- 
pered, and has a very close, dense structure. It is used in 
the manufacture of hand tools, such as hammers, chisels, 
etc. A discussion of the strength of materials will be found 
in Part VII. 

QUESTIONS 

1. Why is it important that a good quality of material be used in 
the construction of farm machinery? 

2. Discuss the merits of wood as a material for farm machinery. 

3. Describe some of the special uses for wood. 

4. Why is hickory used for wagon axles and buggy spokes? 

5. Compare white oak with hickory. 

6. Suggest some good uses for maple, beech, birch, poplar, and 
white and yellow pine. 

7. What are some of the properties of cast iron? 

8. Describe the process of making chilled iron. Malleable iron. 

9. For what purposes is cast steel used? 

10. Why are Bessemer and mild steel used so largely in the con- 
struction of farm machinery? • 

11. Describe soft-center steel and its uses. Also tool steel. 

12. What is tool steel, and mention some of its properties? 

Note: Samples of the various materials used in the construction of 
farm machinery should be collected, and machines should be examined 
to determine the materials used. 



CHAPTER XXXII 
THE PLOW 

The Plow. The plow is universally recognized as the 
principal and most fundamental implement used on the 
farm, it being often included in emblems representing the 
great industry of agriculture. The plow is a very simple 
tool, if we consider the walking implement, and the sulky 
or gang plow is not exceedingly complicated. Yet in the 
selection, operation, and adjustment of the plow there are 
many important features to be considered. 

The Selection of a Plow. As with any other imple- 
ment, the selection of a plow will depend in a large measure 
upon the conditions to be met. A farmer owning a farm 
with small fields would not want a steam plow; nor would 
a farmer having large level fields want small walking plows, 
when a single driver could handle a gang just as well. The 
walking plow is useful in small lots and in getting close to 
the fence in finishing up the lands plowed with a larger 
plow, and for these reasons it should be a part of the equip- 
ment of every farm. 

Size. The sizes of plow which should be selected is 
determined largely by the condition of the soil and the 
amount of power or the number of horses available. The 
average size (width of furrow) for a walking plow is 16 
inches, and the horse gang usually has two 12- or 14-inch 
plows, or bottoms, as they are called. 

Types of Plows. There are three distinct types of plows 
upon the market, as classified by the shape of the mold- 
board: First, the breaker, with a long moldboard to turn 



200 



AGRICULTURAL ENGINEERING 



the furrow slice of tough sod gradually; second, the general- 
purpose plow, to be used for general plowing in stubble and 
light sod; and third, the stubble plow, with an abrupt mold- 
board for pulverizing the soil, used only in old ground. 
Among these three classes there are numberless shapes of 
plows difficult to classify. 





108. The Ihive principal typos of- plows, showing in order the 
stubble, the general purpose, and the prairie breaker plows. 



Construction. The moldboard may be made of soft- 
center steel or chilled iron; but the latter is used but very 
little in the Middle West, where the soil is of such a character 
that the hard-tempered surface of the soft-centered steel is 
required to scour properly. Certain localities are furnished 
with plows with common cast-steel moldboards; but they 
can not be used where many rocks are encountered, in 
which case a soft share, at least, must be provided. The 
wearing properties of the soft-centered steel share is secured 
through its hardness; but to secure hardness a certain 

amount of brittleness 
must remain, even with a 
soft center to the metal. 
Adjusting the Walk- 
ing Plow. The walk- 
ing plow must have its 
point turned down 
slightly in order to cause the plow to take to the ground. 
This gives what is called "suction" to the plow, and is 
resisted by the upward pull of the draft. It is imperative 
that the suction be sufficient, and quite as important that 




steel beam walking plow 
jeneral-purpose type. 



FARM MACHINERY 



201 




Pig 110. Illustrating method of 
using a straight-edge to determine 
whether a plow has the proper "suc- 
tion." 



it be not too great. With the proper amount of suction a 
plow will run evenly, as far as depth is concerned. To test 
for suction, lay a straight- 
edge on the underline of 
the landside when the 
plow is turned bottom 
side up. If there is an 
opening of about }/$ of an 
inch between the straight-edge and the landside at the 
joint between it and the share, the suction is about correct. 
To lift and bend the furrow slice, a certain amount of 
pressure must come upon the outer corner, or wing, of the 
share. To resist or carry this pressure, a certain amount 
of surface, or "bearing," is provided to rest upon the bottom 
of the furrow as the plow is drawn along. If this bearing 
is too great, the plow will be continually tending to turn out 
from the land, and if insufficient will turn in the opposite 
direction. The amount of bearing, or the width of surface 
at the corner of the share, varies with the condition of the 

soil, but 134 inches is 
about correct for a 16-inch 
plow. The bearing sur- 
face is triangular in shape, 
and is usually about 3 
inches long. 

Steel-beam walking plows have an advantage in clearance, 
and for this reason are more satisfactory in plowing under 
trash and weeds. On the other hand, wooden-beam walking 
plows are slightly lighter. 

Sulky or Gang Plows. Riding plows with moldboards 
may be divided into two classes, frame and frameless, and 
are constructed with and without tongues. The frameless 
and tongueless plows are of the cheaper construction; but, 




Fig. 111. A share with the proper 
form at the wing. The contact or 
"bearing" at C should be about 1 % 
inches wide for a 16-inch plow. 



202 



AGRICULTURAL ENGINEERING 




Fig. 112. A frameless and tongueless 
sulky plow guided by the hitch. 



although they have the advantage of lightness, they do not 
have certain advantages secured in the frame and tongued 
plows. The frame type has the plow connected to the frame 

by means of bails or some 
similar device. This per- 
mits the plow to be lifted 
high out of the ground, 
designating it a "high- 
lift" plow. This fea- 
ture is a decided ad- 
vantage for cleaning. 
The frameless plow has 
the wheels attached di- 
rectly to the plow beam by means of brackets. This 
simplifies the construction; but frameless plows are not high- 
lift. This type cannot usually be set to "float," so that in 
case a rock is struck in plowing the plow may be lifted out 
of the ground without interfering with the carriage or the 
driver. 

The tongue on the high-class sulky plow is used to steer 
the plow by be- 
ing connected 
to the furrow 
wheels by means 
of suitable link- 
age, thus en- 
abling a square 
corner to be 
turned in either 
direction. The 
tongue gives more complete control over the plow, and, in 
the opinion of the author, is an essential part. Another 
desirable feature to have on any plow is a footlift, which 




Fig. 113. A high-lift frame gang plow. 



FARM MACHINERY 



203 



enables the driver to control the plow by the feet, leaving 
the hands free to drive. The frame plow with a high lift, 
footlift, and tongue has many complications as far as con- 
struction and operation are concerned, but is well worth the 
difference in price over a more simple plow. Gang plows 
have the same constructional features as sulky plows, except 
that two bottoms instead of one are provided. 

The Adjustment of Sulky and Gang Plows. In operat- 
ing the sulky or gang plow, every effort should be made 
to have the plow travel straight to the front and to 
have all of the downward pressure, due to lifting the furrow 
slice, and the side pressure, due to turning the furrow slice, 
borne by the carriage of the plow. 
To do this the point must al- 
ways be turned down sufficiently 
to cause the plow to take the 
ground at all times. No pres- 
sure should be allowed on the sole 
of the plow, as this will cause o 
unnecessary friction. All pres- 
sure as far as possible should 
come on the wheels, which, with 
their lubricated bearings, will re- 
duce friction to a minimum. 

To give the sulky plow suc- 

,• ,i i- ii Fig. 114. A plan of a high- 

tion, the rear furrow wheel may lift frame suiky plow showing 

, , i i-i,! i i cii the manner in which the rear 

be lowered Until the heel 01 the furrow wheel is set to relieve 




the friction on the landside. 



landside lacks about Y2 inch of 
touching when the plow is placed upon a level sur- 
face. To carry the landside pressure, the rear furrow wheel 
should be set outside of the line of the landside, usually 
about 1)4 inches. It must also be turned slightly away 



204 AGRICULTURAL ENGINEERING 

from the land, and the front furrow wheel regulated to keep 
the large land wheel traveling directly to the front. 

Draft of Plows. The draft or pull required to move a 
plow at work varies widely with the soil conditions and the 
adjustment of the plow. The draft will vary from 4 to 10 
pounds to each square inch of cross section of the furrow slice, 
the method of comparision commonly used. In stubble 
ground the draft should not exceed 4}^ pounds per square 
inch of the furrow. Thus a 16-inch plow running six inches 
deep will have a furrow with a cross section of 96 square 
inches. If the draft be 4^ pounds per square inch the total 
draft will be 432 pounds, an easy load for three 1300- to 
1400-pound horses. 

A sulky plow with a driver of medium weight 'will run with 
as light draft, when in proper adjustment, as a walking plow. 
This is due to the reduction of sole and landside friction. A 
plow out of adjustment will often pull half again as heavy as 
it should. 

In making a selection of a sulky plow, care should be taken 
to see that all parts subject to wear can be easily renewed. 
The greater part of a sulky plow is not subject to wear and 
will last indefinitely if not broken. The modern plow 
must have wheel boxes which will not only exclude all dirt 
but also provide a magazine for a liberal supply of grease. 
Many sulky plows are now constructed with too light a frame. 
Choice should be made of the heavy, rigid plow, even if the 
cost is slightly higher and the draft slightly greater. 

The Disk Plow. There are two conditions under which 
the disk plow will do good work. The hard, dry soils of some 
of the Western states are more easily subdued by means of 
the disk plow than any other. These soils at certain times 
of the year are turned up in lumps by the common plow, but 
the disk plow cuts its way through the lumps and breaks 



FARM MACHINERY 



205 



them up. Yet the disk plow cannot be used in extremely 
hard ground, such as might be found in a road, as it could 
not be kept in the ground. The other soil condition to which 
the disk plow is well adapted is where the soil is so sticky 
that the moldboard plow fails to scour well, as in heavy 
clay or gumbo soils. The black, waxy soil found in Texas 
and other parts of the South is such a soil. The disk plow 
with its scraper to clean the disk will turn a furrow regardless 
of the scouring properties of the soil. Where the moldboard 




Fig'. 115. A modern disk gang' plow at work. 

plow will do good work, it is to be preferred to the disk plow. 
As generally constructed, the latter is a very clumsy imple- 
ment and very heavy, the weight being necessary to keep 
the plow in the ground. Claims for its lightness of draft 
cannot be substantiated by tests when compared with mold- 
board plows under favorable moisture conditions. Often 
the disk plow is given credit for doing more work than it 
actually performs, in that the bottom of the furrow is not 
flat and measurements are often made of the deepest point. 
The diameter of the disk proper varies from 20 to 30 
inches in different plows. A 24-inch disk will do the most 
satisfactory work under usual conditions. It pulverizes the 



206 



AGRICULTURAL ENGINEERING 



soil to the best advantage, — more so than a smaller disk, — 
and is not of as heavy draft as a larger disk. A disk blade 
26 or 28 inches in diameter can be used for a longer period, 
because much more metal is provided for wear. 

The disk plow does not have a tongue and does not make 
as good corners as the modern high-class sulky plows. If the 
disk is of proper shape and size, the plow pulverizes and mixes 
the soil thoroughly, which features are essential in good plow- 
ing. This plow will cover standing weeds to good advantage, 
but loose trash is troublesome. It cannot be used at all in 
tough sod. 

It is a mistake to try to cut too wide a furrow with a disk 
plow. A furrow with a width greater than 8 inches results 
in more or less "cutting" or "covering." 

The vital parts of a disk plow are the disk and its bearing. 
The former should be constructed of the best of material, 
for which the faith of the manufacturer must be taken, and 
the bearing should have plenty of material to resist wear 
and reliable means of excluding dirt and providing lubrica- 
tion. 

Deep -Tilling Machine. This is a new machine which 
has come upon the market 'within the last two years, and, as 

far as providing 
a means of plow- 
ing the soil to a 
greater depth 
than hitherto is 
concerned, it is 
a success. The 
machine is a disk 
gang plow with 
the second or 
rear disk set to 

116. A deep-tilling machine. 




FARM MACHINERY 



207 



plow a furrow in the bottom of the furrow made by the first. 
In this way it is entirely possible to plow to a depth of 16 
inches or even more. The disks are large and they do 
the best work when cutting a furrow 12 inches wide. 

The draft of this tool is surprising. When tested in a 
loam soil with a clay subsoil, the draft, when plowing a 12-inch 
furrow and 16 inches deep, was between 800 and 900 pounds. 
A 16-inch sulky plow when forced to its capacity for depth 
(eight to nine inches) gave a draft between 900 and 1000 
pounds, or about 100 pounds more. By comparing the 
sizes of these various furrows it is to be noticed that the draft 
of the tilling machine was very satisfactory. Again, it would 
be quite impossible to plow so deep with anything except a 
special plow o'f this character. 

Hillside and Reversible Plows. The hillside plow is 
a reversible plow adapted to a field with so much slope that 
it would be quite impossible to throw a furrow uphill. The 
plow is changed from a right-hand to a left-hand plow by 
revolving the plow so that the furrow is turned either to the 
right or to the left. 

The reversible plow was formerly confined to the hillside 
type, yet there is a tendency at the present time to make a 
more extended use of 
this type of plow. Its 
use in the irrigated 
sections, where dead 
furrows are to be avoid- 
ed if possible, is of 
great importance. The 
advantage of dispens- 
ing with dead furrows 

C U J 4-U Fig '- 117 - A reversible disk plow. This 

m any nelCt, and tUUS plow is made to turn a right or left fur- 
i • ,i r row by swinging the hitch from one end 

leaving the surface t0 the other. 




208 



AGRICULTURAL ENGINEERING 



level, is worthy of consideration. In Europe, the reversible 
plow has been in more extended use than in this country. 

The moldboard type of reversible plow consists of two 
plow bottoms, a right- and a left-hand, which are used alter- 
nately. These plows do not have many of the conveniences 
of the high-lift sulky and do not possess the usual provisions 
for relieving the landside friction by placing the load on the 
carriage. It is, however, an entirely practical tool. The 
reversible disk plow is so arranged that by swinging the team 
and hitch about to the opposite direction, the inclination of 
the disk is changed, but the carriage is left unchanged and 
is simply drawn across the field in the reverse direction. It 
would seem that this implement has reached a higher state 
of development than its moldboard mate. 

Engine Gang Plows. The use of the steam and the gas 
tractor for plowing requires gang plows built in large units 




grang plow. 



capable of plowing from 3 to 14 or more furrows at a time. 
Both moldboard and disk plows are made in engine gangs. 
In construction, engine gangs consist of a heavy triangular 
frame carried on castor wheels with wide tires. The plows 
are attached to the rear of this frame and are generally con- 
trolled by levers extending forward over a platform on the 



FARM MACHINERY 209 

frame. These levers may be attached either to a single plow 
or to a pair. Quite a little variance is to be found in the loca- 
tion and construction of the gauge wheel which is provided 
for each plow or pair of plows. Any type of plow may be 
used, depending upon the character of the work. One of 
the more recent improvements consists in making the shares 
in such a way as to be easily removed and replaced. 

Adjusting the engine gang consists primarily in setting 
the plows for the proper amount of suction and proper spac- 
ing. The gang should be attached to the tractor so as to 
cause each plow to be drawn straight through the soil. To 
do this the chains used to 'attach the plow to the tractor must 
be so adjusted as to place the center of hitch directly ahead 
of the center of resistance. 

Some large plows used with steam tractors have pro- 
vision for raising the plows by steam. Another plow has a 
self -lift by which the plows are raised with a system of cams 
geared to one of the wheels of the plow. This mechanism 
enables the plow to be controlled by the tractioneer through 
a rope running back from the tractor to the gang to operate 
the clutch, placing the raising mechanism in and out of gear. 

Disk engine gang plows resemble very much horse disk 
gangs, except they are heavier in every respect. The disk 
plow does not have the individual control of the moldboard 
plow. 

QUESTIONS 

1. Why is the plow considered the principal implement on the farm? 

2. What are some of the most important factors to be considered 
in the selection of a plow? 

3. How is the size of a plow designated, and what are some of the 
common sizes? 

4. What are the distinct plow types on the market? 

5. Of what materials are the plow moldboard and share made? 

6. Describe the adjustment of a walking plow. 



210 AGRICULTURAL ENGINEERING 

7. What is meant by the suction of a plow? The bearing at the 
wing? 

8. What is the difference between a frame and a frameless plow? 

9. Describe what is meant by high lift. 

10. How should sulky plows be adjusted? 

11. How is the draft of a plow kept low by adjustment? 

12. What constructional features should be given consideration 
in making a selection of a sulky plow? 

13. Under what conditions will the disk plow work better than the 
moldboard plow? 

14. What are the common sizes of disks and disk plows, and what 
size of furrow will they turn? 

15. Describe the construction of the deep-tilling machine. 

16. Describe the construction of hillside and reversible plows, and 
explain their use. 

17. Describe the construction of the moldboard engine gang. 

18. How are the plows raised and lowered? 

19. What adjustments are of primary importance? 

20. Describe the construction of the disk engine gangs. 



CHAPTER XXXIII 



HARROWS, PULVERIZERS, AND ROLLERS 

HARROWS 

Utility of the Smoothing Harrow. Perhaps there is 
no other tillage tool on the farm which is more effective than 
the common spike-toothed smoothing harrow, when used 
under the proper conditions and at the proper time. It 
smoothes and pulverizes the surface, producing a fine tilth, 
which not only prevents 
a loss of moisture by 
evaporation but also 
destroys a multitude of 
weeds at the time when 
they are the least able 
to withstand cultivation. 

Selecting a Smooth- 
ing Harrow. The stand- 
ard harrow of the day is 
the steel lever harrow 
for four horses, covering a width of 15 feet or more. A 
harrow with a spread of from 10 to 15 feet is a size suitable 
for a three-horse team. 

A lever harrow, which enables the teeth to be inclined 
forward for penetration and backward for smoothing, costs 
slightly more than a plain harrow or even an adjustable tooth 
harrow; but the harrow at most is not an expensive implement 
and the lever harrow is well worth the difference in cost. One 
of the principal advantages of the lever harrow lies in the 
convenience in cleaning. The adjustable tooth has a clamp 




Fig. 119. A modern U-bar smoothing 
harrow with protected tooth bars. A har- 
row cart is attached. 



212 



AGRICULTURAL ENGINEERING 



which permits the teeth to be held in a perpendicular position 
when drawn in one direction or in an inclined position when 
drawn in the opposite direction. The harrow is reversed by 
changing the evener from one side of the harrow to the other. 
All harrows may at first seem alike, yet there is much 
difference in their construction. There is no doubt but that 
some harrows are made as cheaply as possible to sell for a 
low price. Of course there are conditions where the soil is 
easily cultivated and a light harrow is desirable; yet, as a rule, 
the amount of cultivation performed is in proportion to the 
weight and number of teeth in the harrow. Stony ground 
will require a heavier construction than would otherwise be 
necessary. 

Construction of the Smoothing Harrow. The tooth 
bars are commonly made of the so-called U bar or pipe. The 
former seems to be the stronger for the weight of metal 
used. The teeth may be had in two sizes, one-half or five- 
eighths inch square, the 
larger, of course, being 
adapted to heavy serv- 
ice. All the teeth 
should have large heads 
to prevent loss should a 
fastener become loos- 
ened. The number of 
teeth varies from six to 
eight per foot of width. It stands to reason that the greater 
number of teeth will do more in pulverizing the soil. 

For use in orchards, the harrow with protected tooth 
bars has a decided advantage, since the bars will not do 
much damage by catching upon the trees. As a smoothing 
harrow is too wide to pass through the average farm gate, it 
should be convenient for dissembling and assembling. 




10. A pipe-bar smoothing har- 
Common methods of fastening 
teeth are illustrated. 



FARM MACHINERY 



213 




121. A spring-tooth harrow. 



The Spring-Tooth Harrow. The spring-tooth harrow, 
with flat spring teeth bent almost to a complete circle, is a 
tool that is not in general use in America, but implements 
of a similar character are used to a large extent in Europe. 
It should be classed as 
a cultivator rather than 
a harrow. It is adapted 
to hard, compact soils 
which require a tool of 
good penetration. The 
teeth have such long 
blades with so much 
spring that the machine 
is not damaged in passing over stones or low stumps. 
The draft of a spring-tooth harrow will depend upon the 
adjustment given to the teeth, but under average condi- 
tions it greatly exceeds that of a smoothing harrow. 

The Harrow Cart. Probably there is not another imple- 
ment attachment that can be bought for the same money that 
will dispense with so much hard labor as the harrow cart. To 
be a satisfactory device it must be rigidly built with angle or 
U-bar arms extending to the harrow evener, with provision 
for the cart wheels to castor in turning. The wheels should 
be high, 32 inches being a good height, and provided with 
tires about three inches wide. They should also have dust- 
proof removable boxes with easy means of lubrication. 
Lastly, it should not be overlooked that the cart should 
be provided with a comfortable seat and springs to support it. 

Utility of the Disk Harrow. The disk harrow is an 
implement well adapted to deep surface cultivation. For 
this reason it is used for a variety of purposes. To prepare 
plowing for seed in the spring or stubble for plowing in the 
fall, it is equally useful. For covering broadcasted seed in 



214 



AGRICULTURAL ENGINEERING 



corn stalk ground it has many advantages over the shovel 
cultivator. In the first place it is more rapid, and, more- 
over, a double disking will effectively reduce the stalks. 
In subduing a sod, there- is no other tool that will do the 
work of the disk harrow. In dry-farming localities it has 
been found to be one of the best tools to produce a soil 
mulch for preserving the soil moisture. Orchardists use it 




122. A disk harrow at work. 



for cultivating orchards. It is used in renewing alfalfa fields, 
as it cuts or splits the crowns of the plants, thus thickening 
the stand. 

The disk harrow can be made to do the work of the stalk 
cutter and at the same time cultivate the ground in the early 
spring, preparing it for plowing. As a rule two diskings will 
not cut corn stalks as well as going over the field once with a 
stalk cutter, but nevertheless a good job is done. This 



FARM MACHINERY 



215 



system of disposing of the stalks and cultivating the soil be- 
fore plowing cannot be too highly commended. Many 
weeds are destroyed and a better seed bed is obtained upon 
plowing. 

Construction of the Disk Harrow. The standard disk 
harrow has full round disk blades, sixteen inches in diam- 
eter and about sixteen in number, spaced six inches apart. 
This is the four-horse machine. Smaller disk blades do 
not give sufficient clearance, and larger sizes do not do 
as effective work. The sixteen-inch disk rotates faster than 
a larger disk and so pulverizes the ground more, and it also 
has less bearing surface under the working edge, insuring 
greater penetration. 

Disk harrows have one lever by means of which both 
disk gangs are adjusted at the same time, or two levers, one 
for each gang, permitting individual adjustment. The two 
levers are almost essential when "lapping half," or allowing 




Fig. 123. A full-blade, two-lever disk harrow with tongue truck. 



216 



AGRICULTURAL ENGINEERING 




124. A cutaway disk harrow. 



the disk to extend half way over the work of the previous 
round. The merit of this method lies in the fact that the 
ground is left nearly level, while a single disking will leave the 

ground slightly ridged. 
When this method is fol- 
lowed, the disk gang work- 
ing on the once disked 
ground finds less resist- 
ance than the gang work- 
ing in the undisked ground. 
By setting the gang in 
the loose soil at a sharper 
angle, the machine is balanced and the soil pulverized more 
than otherwise. The two-lever machine also has a decided 
advantage in hillside work. The tendency of the machine 
to crowd downhill may be overcome to a large extent by 
a separate adjustment of the gangs. 

Types of Disk Harrow. Disk harrows are built in 
three general types, as far as the construction of the disk is 
concerned. First, there is the full-bladed disk with solid per- 
fectly round edges; second, the cutaway or cut-out disk, 
which is like the full-bladed disk except that notches are 
cut out of the edge, leav- 
ing short points to enter 
the ground; third, the 
spading disk harrow 
which consists of a series 
of sharp blades curved at 
the end and made up into 
a sort of sprocket wheel. 

For average conditions the full-bladed disk is the best. 
It has a greater pulverizing action, is stronger, and is more 
effective in cutting up trash and stalks. Another very im- 




disk harrow. 



FARM MACHINERY 



217 



portant advantage of this type is the convenience of sharpen- 
ing. These disks may be sharpened to a good edge by means 
of any of the disk sharpeners which will do 
good work. About the only way that the 
notches of the cutaway disk may be sharpened 
is by removing all of the disks and grinding 
them to edge on an emery wheel. The blades 
of a spading harrow are sharpened by heating 
each individual knife and drawing out the 
edge with a hammer while hot. 

The cutaway harrow is very deceiving in 
the amount of work it does. The blades 
sprinkle the soil over the surface in such a way 
that the unstirred soil underneath is hidden. 
This harrow has a decided advantage in cul- 
tivating and renovating old pastures. Where 
the full-bladed disk would cut the stubble up 
and destroy it, the cutaway will loosen the 
soil in such a way as to stimulate growth. 

In the amount of work done, the spading 
harrow is much like the cutaway. The prin- 
cipal advantage of the spading harrow lies in 
its ability to work in wet ground, when the full-bladed 
disk would be sure to clog. 

The "plow cut" disk has a bulged or raised center, it being 
claimed that the soil will be more nearly turned over when 
coming in contact with this center. The name might imply 
some sort of plow action, but the work of this type, as far as 
the writer has observed, does not differ much from the 
ordinary disk harrow. 

Alfalfa Harrow. The alfalfa harrow is a special tool 
with sharp spikes arranged as disks in the frame of a common 



Fig. 126. A 
plow-cut disk 
used on disk 
harrows. Note 
the raised 
center. 



218 



AGRICULTURAL ENGINEERING 




An alfalfa harrow. 



disk harrow. This new implement is certain to become 

very popular for cultivating alfalfa fields. 

Scrapers. A disk harrow should be provided with 

scrapers or cleaners which 
will keep the disks clean 
imder all conditions. The 
scraper with a rather nar- 
row chisel blade which 
can be moved from the 
center to the outside of 
the disk is very satisfac- 
tory and is used upon 

a large number of modern disk harrows. 

Bearings. The part that receives the most wear, except 

the cutting edges of the disks themselves, is the bearings. 

Both chilled iron and wooden boxes are used. The wood 

seems to be the more satisfactory, not only on account of 

durability, but also on account of the ease of replacement. 

Maple boiled in oil is generally used for the bearings, yet any 

hard wood might answer. 

Ball-and-socket joints between the disks are not generally 

satisfactory. If the bearings 

do not care for the entire 

thrust of the gangs, bumper 

plates seem to be the most sat- 
isfactory devices. These are 

large oval washers on the ends 

of the gang bolts which run Fig 

through the center of the disks. 

Tongue Truck. The modern disk harrow has a tongue 

truck. This device relieves the horses of the most tiresome 

part of the work when the harrow is used on loose and rough 

ground. With a tongue truck, side lashing is prevented. 




128. A good form of bearing 
for disk harrows. 



FARM MACHINERY 



219 



Trucks which have tongues assist in keeping the team straight 
and also prevent the horses from backing into the harrow. 
The trucks should have reasonably large wheels and be 
strongly made. The axles should provide for lubrication, 
be dust proof, and have interchangeable boxes. 

Transport Truck. Another convenient devioe to use in 
connection with the disk harrow is the transport truck, 
especially if the harrow is to pass over any hard road. This 
device consists of wheels mounted on levers in such a manner 
that the gangs may be lifted from the ground, thus securing 
the desired protection. 




A harrow attachment for a plow at work 



Harrow Attachments for Plows. Those who have had 
the experience know that a harrow will do the most effective 
work when following the plow. Attention has been called 
by agricultural writers to the desirability of harrowing each 
day's plowing before the close of the day. The harrow attach- 
ment has been designed to harrow and smooth each furrow as 
soon as turned. There are three types in use, one with blades 
which resemble those of a pulverizer, another is a rotary 
affair with blades like a spading disk harrow, and still another 



220 



AGRICULTURAL ENGINEERING 



kind has small round disks. Each of these works much like, 
the machines after which they are patterned. They are 
made in sizes suitable for either sulky or gang plows, and 
are quite easy to attach. They interfere slightly with the 
adjustments of the plow, but this matter can easily be over- 
come. The draft of those for sulky plows will vary from 
50 to 100 pounds, depending upon the pressure applied. 
This means that the attachment provides about one-half 
to two-thirds of a load for one average horse. 

LAND ROLLERS 

Types of Rollers. The plain, smooth land roller has 
been replaced to a large extent by tubular, corrugated, or 

disk types. The change 
has been due to some of 
the objectionable features 
of the work of the smooth 
roller. It is desirable, in 
most instances, not to 
leave the surface of the 
ground perfectly smooth 
and compact. It is true 
that for crops to be har- 
vested with the mower 
this feature is desirable, but a smooth surface usually means 
an unnecessary loss of moisture. On a smooth surface there 
is no soil mulch, and the 
wind has a greater dry- 
ing effect. 

Of the various types, 
of rollers recently placed 
upon the market, the 
disk roller, composed of 




Fig-. 130. A plain land roller. 




FARM MACHINERY ■ 221 

cast-iron disks with wedge-shaped treads, spaced about 
four inches apart and weighing about 100 pounds per 
foot of width, is perhaps the most satisfactory. This imple- 
ment not only thoroughly packs the soil beneath the surface 
but aslo collects and crushes the clods and leaves the 
surface slightly rough and covered with a mulch. 

Selecting a Roller. In selecting a roller, the bearings, 
strength of construction, and weight are the principal fea- 
tures which should be given consideration after the type 
of machine has been decided upon. Hard-wood boxes 
make the most satisfactory bearings. If the ground is 
uneven, a flexible frame should be chosen, as there will not 
only be less chance of breakage in the roller but better work 
will be performed. 

PULVERIZERS 

The name pulverizer is given to a variety of tools. It 
usually designates certain curved-tooth harrows of the Acme 
type and also rollers of the 
cast-iron type. In some 
localities the disk harrow 
is referred to as a pulver- 
izer. It seems, however, 
that the implement best 
described by this name Fi s. 132 - A pulverizer with rake 

attached. 

is the one with curved 

spring knives, either with or without a leveling rake. This 
tool has not become very popular with farmers generally, 
but it seems to be gaining favor of late. The tendency 
has been to try to perform the same work by means of 
the common smoothing harrow. 

The pulverizer does efficient work in producing a fine 
tilth. It is especially useful in destroying small weeds just 




222 AGRICULTURAL ENGINEERING 

coming through the ground. The knives tear the weeds 
out and the rake behind drags them free of the soil and leaves 
them on the surface to be destroyed by the sun. The drag- 
ging action of the pulverizer is also very good in leveling an 
uneven surface. The draft of the pulverizer is less than 
that of the disk harrow, an eight-foot pulverizer drawing 
about as hard as a six-foot disk harrow. 

QUESTIONS 

1. What is the work of the smoothing harrow? 

2. Describe the difference in construction between the adjustable 
tooth harrow and the lever harrow. 

3. Describe some of the important constructional features of the 
smoothing harrow. 

4. Describe the construction of the spring-tooth harrow, and under 
what conditions it will render the best service? 

5. Why is the harrow cart useful and what should be its construc- 
tion? 

6. For what work is the disk harrow adapted? 

7. Describe some of the general features of the construction of the 
disk harrow. 

8. What are the three general types of disk harrows? 

9. Describe the plow-cut disk blade. The alfalfa harrow. 

10. What is the purpose of the scrapers on a disk harrow? 

1 1 . Why are the bearings important on a disk harrow? 

12. Of what use is a tongue truck? 

13. Describe the construction of harrow attachments for plows. 

14. Describe three types of hand rollers. 

15. Explain some of the important points to be considered in select- 
ing a hand roller. 

16. To what purpose is the pulverizer adapted? 

17. Describe the construction of the curved-tooth pulverizer. 



CHAPTER XXXIV 



SEEDERS AND DRILLS 

Utility of Seeders and Drills. The seeder should be used 
only where the drill is impractical, as it is not a machine 
adapted to the most improved methods of farming. The 
drill enables all the seed to be covered at a uniform depth 
and to be very uniformly distributed. The broadcast seeder 
may distribute the seed uniformly, but the harrow or other 
implement which follows it will not cover the seed at a uni- 
form depth, meaning that a part of the seed is placed too 
deep and a part too shallow. The saving of seed alone in 
sowing a large field is often sufficient to practically pay for 
a drill. There are certain seeds, however, that must be 
covered very shallow, and the modern drill is not well adapted 
for the purpose. At one time grass seed was broadcasted 
on meadows to thicken the stand, but the drill has been 
found to do this work more satisfactorily. 

SEEDERS 

Hand seeders are used on rough ground where horse 
machines can not be used. A very satisfactory type is the 
crank machine with a whirling distributor. It is not possible 
to secure a very even seeding in 
this way, but that is often quite 
unavoidable. This type of machine 
should have an agitator for feeding 
the grain to the distributor. No 
attempt should be made to use the 
machine on a windy day. 




224 



FARM MACHINERY 




Fig. 134. A wheelbarrow seeder. 



The wheelbarrow seeder is preferred by some in sowing 
grass seed. At one time the grain seeder lacked refinement 
for grass seeding. The wheelbarrow seeder usually has an 
agitator feed, which is not accurate, to say the least. This 

agitator consists of a 
rod beneath the seed 
box which stirs the 
seed in such a manner 
as to cause it to flow 
out of the opening on 
the under side of the box in a fairly uniform stream. 

Endgate seeders have one desirable feature, and that 
is their great capacity. The seeding, however, is never very 
uniform. As far as known, all machines of this class have 
whirling distributors, which are either single or duplex. The 
latter are claimed to have more capacity and to be more 
accurate than the single distributor machines. To improve 
their accuracy some makes of 
endgate seeders are provided 
with a force feed to the dis- 
tributor. There is no doubt 
but that this is a good feature 
and should be on all such seed- 
ers. Friction and gear drives 
are used to drive the distribu- 
tor. Spiral gears seem to be 
the most satisfactory, but 
care should be used in starting the machine so as not to 
cause breakage. 

Seed-box broadcast seeders are used to a considerable 
extent. These are commonly eleven feet wide and mounted 
either upon wheels at each end of the box or upon a low wheel 
truck underneath. The truck type does not lash the tongue 




135. An endgate seeder. 




FARM MACHINERY 225 

so much in passing over uneven ground, and for most condi- 
tions is to be preferred. The box may be placed low, and 
only distributing funnels used to spread the seed, or the box 
may be placed higher and the distributing funnels placed at 
the lower ends of seed tubes. The latter has not been very 
satisfactory, as the tubes are either easily broken or lost. 
The seed, of course, 
should be released quite 
near the ground so as 
not be interfered with 
by the wind. This type 
of seeder may have narrow-track truck. 

either the agitator feed previously described, or a force 
feed. The first type consists of a stirring wheel over an 
opening through which the grain is allowed to flow. The 
force feed is by far the more accurate, and will be described 
under drills. 

DRILLS 

Furrow-openers. Grain drills are now equipped with 
four types of furrow-openers, the single-disk, the double- 
disk, the shoe, and the hoe. An idea of the construction of 
each may be obtained from the accompanying illustrations. 

The single-disk is the best for most conditions. It has 
better penetration and will cut through trash better than 
any other type. Furthermore, it has only one bearing per 
disk to wear out, whereas the double-disk has two. The 
single-disk must have one half of the disk turned in the oppo- 
site direction from the other half in order to keep the machine 
balanced. This is a disadvantage, as it causes the ground 
to be left slighly uneven, which necessitates that the drill be 
followed with a harrow on rolling ground to prevent soil 
washing. The single-disk furrow-opener may be provided 



226 



AGRICULTURAL ENGINEERING 



with a closed boot, which provides a complete passageway 
for the seed to the bottom of the furrow independent of the 




Fig. 137. A standard single-disk drill at work. This machine has IS 
furrow-openers spaced 7 inches apart. 

disk; or with the open boot, which depends upon the disk 
blade to supply one side of the seed tube. The closed form 
is less apt to become clogged, but the open style provides a 
slightly wider seed row. 

The double-disk does not have quite the penetration 
that the single-disk has, but when the disks are quite sharp 
this type of opener is good for cutting through trash. The 
claim is advanced that the principal merit of the double-disk 




Fig. 13S. Single-disk, double-disk, shoe, and hoe furrow-openers for 
grain drills. The single-disk has a closed boot, or shoe. 



FARM MACHINERY 227 

lies in the wide furrow that it makes, with a slight ridge in 
the center. Definite experiments, as far as known, have not 
been conducted to prove any advantage of this kind of 
furrow. 

The shoe drill has been almost entirely displaced by the 
disk drill. It is a lighter draft type, and where penetration 
is not desirable it may be the type to select. The hoe drill 
has good penetration but can not be used where there is any 
trash to contend with. 

Force Feeds. Two types of force feeds are used on drills. 
The most common is the external feed with a fluted seed 




Fig. 139. The external force feed is shown at the left, and the internal 
device at the right. 

shell. The amount of seeding is varied by slipping the shell 
in a guard so as to expose in the seed cups more or less of the 
fluted parts as required. The second type is the internal 
feed with a ribbed ring to which the seed passes on the inside. 
This type does not vary the size of the cells on the ring, but 
the feed regulation is obtained by varying the rotative speed 
of the ring by a change of gears. Usually two sizes of seed 
cells are provided in the ring, one for small seeds and one for 
large seeds. The internal feed is the best type for drilling 



228 AGRICULTURAL ENGINEERING 

large seeds like peas or beans. The cells of the ring, being of 
a certain uniform size, will not crush the seed like the external 
feed. For small grain the external feed, however, is the most 
accurate and is the most convenient of adjustment. This 
type will drill at a quite uniform rate regardless of the amount 
of seed in the seed box. 

Press Drills. The press drill with press wheels to follow 
each furrow-opener is the most satisfactory type for fall seed- 
ing. The press wheel packs the soil firmly around the seed, 
causing the moisture to come up from below by capillary 
action and thereby producing early germination. For spring 
seeding, when there is an abundance of moisture in the soil, 

the press wheel is a dis- 
advantage. In regions 
where both spring and fall 
seeding are practiced, the 
press wheel attachment, 
which can be used when 
desired, is a satisfactory 
arrangement. 

Selecting a Drill. In 
selecting a drill with disk 

A press drill. r ,, , 

furrow-openers, the bear- 
ings and the means of oiling the bearings should be care- 
fully inspected. The bearings are the first parts to wear 
out. A good strong frame is important, as well as a 
trussed and braced seed box. The best designs do not 
depend upon the seed box to support the drill, except in a 
minor way. 

Seed Tubes. Rubber, wire, and steel ribbon seed tubes 
are used on drills. The rubber tubes are quite satisfactory, 
but are not durable, especially if not well protected from the 
weather. Steel wire tubes are satisfactory except when 




FARM MACHINERY 



229 



stretched, when there is no way of shortening the tubes and 
filling the cracks. The steel ribbon is no doubt the best of 
all, as it is affected only by rust. 

Adjustment. The furrow-openers 
should have a convenient means of ad- 
justing the spacing. A double drag-bar 
is without doubt preferable to the single 
one. The common spacings of furrow- 
openers are six, seven, and eight inches. 
For the average conditions, seven inches is 
a very satisfactory spacing. Seven-inch 
drills are usually made with 12 or 18 fur- 
row-openers. The latter is a good size 
suitable for four horses, and will cover 
three corn rows of 3 3^2 feet each. 

Horse Lift. The horse lift for large 
drills is a great convenience. To be com- 
plete, the drill should have a grass seed Fig. in. a section 

, . i . .... ! . , of the seed box of 

attachment, permitting grass seed to be a arm showing ioca- 
drilled with other crops. The footboard bo" Ld aSnb. 
is preferred by some to a seat. This is bon tube " 
a matter largely of personal preference, but the footboard 
permits the driver to shift from one side to the other 
to manage the driving better. A double capacity or auxiliary 
seed box may now be had with many drills. This obviates 
the necessity of filling the seed box so often. 

QUESTIONS 

1. What advantage has the grain drill over the seeder? 

2. Describe the use and construction of hand and wheelbarrow 
seeders. 

3. How is the grain distributed with the endgate seeder? 

4. Describe the various methods of constructing the seed-box 
broadcast seeder. 




230 AGRICULTURAL ENGINEERING 

5. What two types of feed are used in broadcast seeders? 

6. Describe the construction and the relative merits of the various 
types of furrow-openers used on grain drills. 

7. Describe two types of force feed for drills. 

8. For what conditions is the press drill adapted? 

9. What are the important features to be considered in the selection 
of a drill? 

10. Of what material are the seed tubes made? 

11. What is the common spacing of furrow-openers? 

12. What is a horse lift for a drill? 



CHAPTER XXXV 
CORN PLANTERS 

Essentials of a Corn Planter. The modern corn planter 
is a highly-developed implement and well able to meet 
the exacting demands made upon it. A good planter will 
fill the following conditions: 

First, a corn planter is expected to place in every hill a 
certain number of kernels of corn. 

Second, the corn must be placed at a uniform depth, 
regardless of the condition of the soil or trash that may inter- 
fere. 

Third, the check-rower must place the corn accurately 
in rows for cross cultivation. 

Fourth, the planter must be convenient to operate. 

Fifth, the planter must be capable of adjustment to the 
planting of cane, beans, and several of the other crops grown 
on the general farm. 

No doubt accuracy is the first requisite of the modern 
planter. In selecting a planter, therefore, the dropping 
mechanism should be given first consideration. 

The Dropping Mechanism. There are two distinct 
types of dropping mechanism upon the market, the full-hill 
drop and the accumulative drop. In the full-hill drop a seed 
cell is provided large enough to contain the desired number 
of kernels for one hill (as three, for instance) . These three 
kernels are all counted out at one time, and if they should 
be slightly undersized it would be easy for a fourth to slip 
in as the seed plate containing the seed cell passed under the 
seed box. 



232 AGRICULTURAL ENGINEERING 

The accumulative drop, on the other hand, provides seed 
cells in the seed plate only large enough to contain one kernel 
at a time. The hill is formed by receiving in a receptacle 
the desired number of kernels from as many cells. The 
accumulative drop would appear at once to be the more 




Fig. 142. A modern corn planter with long shoe furrow-openers, vari- 
able drop, and open wheels. 

accurate of the two types, and it may be demonstrated that 
it is, when seed corn graded to size is used. As the cell in 
the accumulative drop is made to contain one kernel only, 
it is evident that great care must be used in making the cell, 
and even then there will be difficulty in caring for odd-shaped 
kernels whose volume may not be much different from the 
average. These ill-shaped kernels are those from the butts 
and tips of the ears, and when an accumulative drop planter 
is used they must be discarded. 




FARM MACHINERY 233 

The edge-selection drop, now quite generally used by- 
manufacturers, is an accumulative drop with the cells in the 
seed plate constructed deep and narrow to receive the kernel 
on the edge instead of on the flat, as ar- 
ranged for in the so-called flat plate. 
The edge-selection plate provides very 
deep seed cells from which there is little 
possibility of the corn being dislodged selection and round- 

, ., , „,. , . , ., ln hole seed plates. 

by the cut-on which covers the cell as 
it passes over the receiving receptacle. There is danger, 
however, of the kernel becoming damaged by being caught 
in the cell on end in such a way that the cut-off cuts the kernel 
in two. 

Graded Seed. The planter will do more accurate work 
if provided with carefully graded corn, and this fact should 
never be overlooked. After removing the butts and tips, 
the corn should be run through a good corn grader, and 
then there should be a careful selection of plates to suit the 
corn to be planted. Different varieties of corn and corn 
from different localities differ much in size and shape, and 
accuracy of drop can only be secured when the plates are 
carefully selected for the corn at hand. Sometimes the 
proper plates are not furnished with the planter, and new 
plates better suited for the corn at hand must be secured 
from the manufacturer. There are usually three sizes of 
plates furnished with each planter, and these will accommo- 
date nearly all of the variations. 

The variable drop mechanism is of recent origin. By its 
use the seed plate is made to count out from two to four ker- 
nels by simply shifting a lever to the designated notch. This 
device can be used to best advantage in hilly fields where 
the fertility of the soil varies much, enabling fewer kernels 
to be planted in the hills where the soil is thin. 



234 



AGRICULTURAL ENGINEERING 




It also dispenses with many of the plates which must be 
furnished with a planter that does not have the device. 
Furrow-openers. The long shoe furrow-opener is in 

more general use than any 
other type. It has good 
penetration and is easy to 
guide. Where there is 
trash in the way, the stub 
runner, which hooks un- 
der the trash, should be 
used. The single-disk 
furrow-opener has good 
penetration and should be 
used in soil that often 
becomes very compact 

Fig. 144. A corn planter with stub shoe before the COm Can be 

furrow-openers. 

planted. It is quite im- 
possible to make perfectly straight rows with the disk 
planter. The bearings of the disks are subject to wear, and 
the single disk throws the 
earth to one side in open- 
ing the furrow, making 
the covering difficult. The 
double-disk furrow-opener 
offers additional compli- 
cations without material 
advantages. It is some- 
times maintained that the 
disk planter is of lighter 
draft. Even if this be 
true, the planter under any circumstances is not a heavy 
draft implement. 

Wheels. The accepted type of wheel for corn planters 




A corn planter with disk fur- 
row-openers. 



FARM MACHINERY 235 

is the open wheel. The wheel is depended upon to cover 
the corn and pack the soil over it. To do this, the open 
wheel not only offers an improvement over the flat or concave 
wheels, but is much easier to keep clean. The open wheel 
has two tires about one and one-half inches wide and set 
about two inches apart. These two tires are so set as to 
draw the soil together over the furrow made by the furrow- 
opener. 

The double-wheel type has two wheels to follow each 
furrow-opener. These wheels 
are capable of being adjusted 
so as to draw the earth over 
the furrow as desired. Corn 
planter wheels are made in 
various heights to accommodate 
the machine to the varying 
conditions as they may arise. Fig . ueT The open and double 
Thus, in certain sections, the type of corn p,anter wheels " 
corn is planted in furrows made by the lister, and, to span the 
high ridges between the furrows, very high wheels are 
necessary. 

Conveniences. There are many devices to be found on 
the modern planters which are designed to save time. The tip- 
over seed box is one. Thus if it is desired to change the seed 
in a seed box for any reason it is not necessary to pick out 
the seed corn kernel by kernel. A wheel on which to wind 
the check wire as the last row is planted is another convenient 
device. There are two general forms of reels in use; one is 
hung under the seat, and the other is placed on a bracket 
over the planter wheel at either side. The first location is 
the most convenient when preparing to reel the wire; but the 
side location permits the wire to be reeled as the last row is 
planted, the reeling being in plain sight of the driver and 




236 AGRICULTURAL ENGINEERING 

there is no necessity of crossing the wire with the team. 
Some friction device must be used to drive the reel. 

The double marker, or a separate marker for each side 
and which may be raised to a vertical position when not in 
use, is undoubtedly the most convenient marker. There 
is less time consumed in putting it in use and there is no 
crossing of the lines with the draw rope. Where the soil is 
hard the disk marker should be used in preference to the 
drag head marker. 

Adjustment. In addition to a selection of the proper 
seed plate, or calibration of the planter, as it is sometimes 
called, the machine should be kept in proper adjustment and 
good working condition when in the field. One of the more 
usual neglects of this kind is the failure to keep the planter 
"front," the part of frame which supports the runners, 
level. If the front be tipped back or forward, the corn will 
be deposited in hills back or ahead of its proper location and 
will not form perfect rows crosswise. 

QUESTIONS 

1. What are the essentials of a good corn planter? 

2. What is the difference between the "full hill" and the accumula- 
tive drop? 

3. Why is it important to have graded seed? 

4. What is the variable drop? 

5. Describe the various styles of furrow-openers used on corn 
planters, and give their merits. 

6. What types of wheels are used? 

7. What are some of the conveniences used on modern planters? 

8. How should planters be adjusted for accurate check-rowing? 



CHAPTER XXXVI 
CULTIVATORS 

Development. The development of the corn cultivator 
exemplifies and typifies the development of agricultural 
methods during the past century. Originally, corn, or maize, 
to be more accurate, was planted and cultivated almost 
entirely with the hoe. Later, the single- or double-shovel 
cultivator was introduced to assist the hoe. Still later the 
straddle or single-row cultivator was developed. At the 
present time the double-row cultivator is typical of modern 
methods. The single- and double-shovel cultivators have 
been discarded from field operations, and only the single- 
and double-row cultivators are left. 

Selection of a Cultivator. Whether or not the double-row 
cultivator can be made to do the same quality of work with 
greater economy than the single-row is a question that many 
farmers are trying to decide. The solution of this problem 
will depend largely upon local conditions. It is unquestion- 
ably true, however, that the successful use of the two-row 
cultivator depends upon careful farming at all times in pre- 
paring the ground and in planting and tending the crops. 
The two-row cultivator is not an implement well designed 
to select and destroy individual weeds, nor is it capable of 
being adjusted to cultivate each hill of corn, regardless of 
whether or not that hill may be in a straight row. The two- 
row cultivator is used successfully where good farming sup- 
plies fields comparatively free from weeds, well-prepared 
seed beds, and straight corn rows. If this high-class farming 
is practiced, the two-row cultivator will be found a necessary 




238 AGRICULTURAL ENGINEERING 

part of the equipment of the modern corn grower. The use 
of the two-row cultivator is a question upon which opinions 
of some of the best farmers differ. This indicates that, in 
addition to the necessary field conditions mentioned, the 
personal factor is one that makes for success or failure. 

Walking Cultivators. The walking cultivator is made 
both with and without a tongue. The advantages of the 

tongueless kind are that 
they are light and re- 
quire less turning room 
than the other. The 
difference in cost is small. 
On the other hand, the 

Fig. 147. A tongueless walking; culti- tOngUeleSS Cultivator 
vator with wooden gangs. 

works very well only 
with a well broken and evenly-gaited team. 

Cultivator Construction. As one- and two-row cultivators 
have many features in common, they will be discussed to- 
gether. Perhaps the most important feature to be decided 
upon in the selection of a cultivator is the shovel equipment. 
Shovel cultivators are provided with from four to eight 
shovels for each two gangs. By gang is meant the 
beam, the shanks, and the shovels attached thereto. The 
four-shovel cultivator is adapted to deep cultivation; 
the six and eight to more shallow cultivation, covering the 
space between the rows more thoroughly but less deeply. 
With a large number of shovels and shanks, the gangs 
become easily clogged with trash if the ground is not entirely 
free from it. A compromise is represented by the six-shovel 
cultivator, which is the most popular throughout the corn 
belt. 

The cultivator beams are now quite generally made of 
steel, although wooden beams may be purchased. Although 



FARM MACHINERY 



239 



slightly heavier, the steel beam is not so easily clogged with 
trash. The shanks may also be of steel or wood, with the 
same advantages. A break-pin device or a spring trip 
should be provided to prevent breakage of the shank if a 
root or stone be struck by the shovels. The best cultivator 
shovels are made of soft-center steel hardened so as to 
take a bright polish. 

The widths of the shovels vary from two to four inches, 
and the wider shovels may be twisted so as to assist in throw- 
ing the furrow to one side. The straight shovels are adjust- 
able upon their shanks to accomplish the same results. 
Where shallow cultivation is desired without a surface culti- 
vator, the spring-tooth cultivator, with four to eight small 
teeth mounted upon springs, is successfully used. 

The coupling of the beam to the frame is one of the most 
important features of the cultivator, for it must enable the 
beam to be shifted horizontally and vertically and at the 
same time cause the 
shovels to remain in a 
vertical position. In 
order that this part of 
the cultivator shall ren- 
der long service, due 
provision must be 
made for adjustment 
for wear. 

The gangs should 
be so suspended that 
they will swing in a 

horizontal plane and not be lifted from the ground when 
swung to one side. Since there is a tendency to advance 
the shovels as they are swung to either side, it is easy to see 
why a long beam is more easily guided than a short one. 




14S. A riding cultivator with balanr 
frame and hammock seat. 



240 AGRICULTURAL ENGINEERING 

As the long beam is swung to one side it does not advance 
so much, because it travels in the arc of a larger circle. 

Due provision should be made for varying the width 
between the gangs to suit the various conditions which may 
arise. This adjustment should be easily and quickly accom- 
plished. The wheels should also be adjustable to various 
widths. Many cultivators are now made with reversible 
axles; that is, the axles are made in the form of the letter Z; 
one of the two ends, which are alike, is attached to the culti- 
vator and the other end serves as the axle proper. After 
the one becomes worn, the ends may be reversed and a new 
wearing surface presented. 

Wheels. The wheels of a cultivator should be high and 
have wide tires which will not carry dirt up on the inside. 
Often the value of a 'cultivator is indicated by the construc- 
tion of the wheels. To determine their strength, the width 
and thickness of the tires and the number and diameter 
of the spokes should be observed. The wheels should have 
interchangeable boxes which may be replaced after they are 
worn without requiring an entirely new wheel, and these 
boxes should be dustproof or long distance. To describe, 
the wheel is held in place by a collar on the inside arranged 
to exclude the dirt and dust, and the outer end of the wheel 
box is enclosed. The end of the wheel box had best be remov- 
able for filling with axle grease or hard oil. A supply of 
grease in one of these inclosed boxes will last for a long time. 

Balance Frame. The balance frame now generally used 
on cultivators has two purposes; first to balance the weight 
of the operator on the wheels; and, second, to balance the 
cultivator when the gangs are carried out of the ground. 
The balance frame makes provision for setting the wheels 
forward or backward as required. It should be a feature 
of every riding cultivator. 



FARM MACHINERY 



241 



Guiding Devices. To guide or steer cultivators, the 
tongue or the wheels are often pivoted and connected to 
levers in such a way as to be conveniently operated. 
The pivoted tongue enables the operator to vary the angle 
with which the tongue is attached to the cultivator. The 
tongue may be attached to a treadle to be worked by the feet 
and used continually for 
guiding the cultivator, or 
it may be attached to a 
lever, permitting adjust- 




Fig. 149. A two-row cultivator with 
straddle seat placed well to the rear. The 
gangs are guided by a treadle device. 



ment for hillsides or for 
the team when they can- 
not be driven true to 
the row. 

Some form of treadle 
guide must be provided 
with the two-row cultivators, as it is not possible to guide 
each pair of gangs independently. The treadle guide may be 
attached to the gangs only, or it may govern the direction of 
wheels at the same time. It is claimed that this double 
arrangement requires less effort on the part of the operator, 
for it is only necessary to change the direction of the wheels 
and the team must do the work. On the other hand, the 
shifting of the gangs alone gives a much quicker action. 

Seats. The seat of the riding cultivator is made in two 
forms, the straddle seat and the hammock seat. The first 
is placed upon a stiff arm extending back from the frame, 
and the second has the seat suspended on a metal strap be- 
tween two arms extending back from the frame. The stradle 
seat is more rigid and is universally used on lever and treadle- 
guided cultivators. The hammock seat offers a good oppor- 
tunity to operate the gangs with the feet, as the seat support 
is not in the way. 



242 



AGRICULTURAL ENGINEERING 




A surface cultivator. 



anything but satisfactory. 



Surface Cultivators. The surface cultivator is apparently 
gaining favor throughout the corn belt. It is provided with 

long flat shovels which shave 
the ground from one to two 
inches below the surface, cut- 
ting off the weeds and pulver- 
izing the surface. The sur- 
face cultivator is a special 
implement. It has been the 
author's experience that go- 
pher or surface shovels at- 
tached to the shovel cultivator 
with an extra arch between are 
It is quite necessary that the 
gangs be of very rigid construction or the shovels will not 
run at an even depth and will not be easily controlled. 
The surface cultivator 
will work satisfactorily 
only where the ground is 
in good tilth and free 
from trash. 

The Disk Cultivator. 
The disk cultivator is 
preferred by some corn 
growers. It is generally 
used in connection with 
the weeder or for listed 
corn, as it moves consid- 
erable soil in one .direction, either to or from the corn. 
Strength and durability of the parts, especially the bear- 
ings, are the important things to consider when making 
a selection. 




puuii 



disk cultivator. 



FARM MACHINERY 243 

QUESTIONS 

1. Trace the development of the cultivator. 

2. What are some of the factors which should be considered in mak- 
ing a selection of a cultivator? 

3. What direct and indirect advantages has the riding cultivator 
over the walking cultivator? 

4. Describe the construction of the tongueless walking cultivator. 

5. Describe some of the important features of modern cultivators. 

6. What can you say of the various shovel equipments for culti- 
vators? 

7. Describe a good method of suspending the gangs. 

8. What adjustment should be provided in the cultivator? 

9. What is the purpose of the balance frame? 

10. What is the difference between a pivoted tongue and pivoted 
wheels? 

11. What two types of seats are used on cultivators? 

12. Describe the construction of the surface cultivator. 

13. To what use may the disk cultivator be put? 



CHAPTER XXXVII 
THE GRAIN BINDER OR HARVESTER 

Of all the machines which have been invented and de- 
veloped during the past century, perhaps none has been the 
means of saving more labor than the modern grain binder. 
It has been the main factor in reducing the amount of labor 
required to produce a bushel of wheat from three hours to 
ten minutes, and at the same time has greatly improved the 
quality of the product. 

The grain binder has undergone little change in the last 
ten years, nor is there any important improvement proposed 
or desired at the present time. The test of time has elimi- 
nated from the field the unsatisfactory machines, in spite of 
the fact that the binder is a very complicated machine and 
must often do its work under very adverse circumstances. 
For these reasons this chapter will be a discussion primarily 
of the adjustments of the binder. 

Size. Formerly the standard binder was a 5-, 6-, or 7-foot 
cut machine. More recently, by the use of tongue trucks 
to care for the side draft, the 8-foot machine has become 
popular among farmers who have large areas of grain to cut. 
Under favorable conditions and with large areas the push 
binder of 10- ? 12-, or 14-foot cut may be used economically. 
These machines require at least six horses, and four horses 
are generally used on the eight-foot-cut machines. 

Selection. Convenience and proper range of adjust- 
ment, and adequate means of lubrication are the important 
things to keep in mind in selecting a binder. The variety 
of grains harvested with the grain binder requires a wide range 
of adjustment. 



FARM MACHINERY 



245 




246 AGRICULTURAL ENGINEERING 

Tongue Trucks. The tongue truck is one of the newer 
attachments for the binder, and is a device which is highly 
satisfactory, especially on the wide-cut machines. It is 
quite impossible with these wide machines to arrange the 
hitch in such a way as to overcome side draft. The tongue 
truck is the only satisfactory method of relieving the horses 
of this burden. 

Engine Drive. It has become a quite common practice 
of late to mount a small gasoline engine upon the binder to 
drive the machinery, relieving the horses of all work except 



CANVASS OH APRON 
ELEVATOR 




TWINE BOX 

•/v"^* ^DTATCfiPM ^-<£=»' A DRIVE WHEEL 

/X C-RAIN WHKEL s PLATFORM 

Fig. 153. The harvester shown in Fig. 152, with some of the parts 

named. 

that required in drawing the machine on its wheels. This 
makes it possible to save a crop on wet, soft ground where 
an ordinary binder would fail because the main wheel will 
slip. In extreme cases the binder has been successfully 
mounted upon skids or sled runners and used to save a crop 
where the soil was so wet and sticky that the main wheel of 
the binder would become so thoroughly filled with mud as 
to refuse to revolve. 

Operation of Binders. It should be the pride of every 
binder operator to so manage and adjust his machine that 



FARM MACHINERY 247 

perfect, well-bound bundles will be formed and tied. To 
procure such bundles, attention must first be given to the 
adjustment of the reel, which should so catch and deliver 
the standing grain that it will fall evenly and squarely upon 
the platform apron or canvas. If the grain is straight and 
standing well, the reel should be set far enough ahead and 
low enough that the grain will be slightly bent back over the 
platform when cut off. This will cause it to fall directly 
back at right angles to the cutter bar. Often the grain varies 
in height in different parts of the field, and adjustment of 
the reel should be made from time to time while the machine 
is in motion. 

Again, the proper adjustment of the binder attachment 
and the butt adjuster canvas should not be overlooked. 
In all machines these two parts are adjustable. The binder 
attachment may be slid forward and backward, enabling 
the operator to place the band nearer the head or the butt of 
the bundles as he may desire. In like manner, the butt ad- 
juster may be set so as to push or pat the straw into an even 
bundle at the butt end and to push the straw back more or 
less as desired. 

Sometimes a binder will give trouble in tearing the slats 
from the canvas. This trouble is due to the fact that the 
rollers over which canvases pass are not parallel or square 
with the frame. If trouble of this kind occurs, the elevator 
frames and rollers should be immediately trued up. Pro- 
vision for adjustment is found on all machines, and the car- 
penter's square will be found a useful means of securing 
accuracy. 

The main drive chain of a binder, if run too loosely and if 
dry or muddy, has a tendency to climb the sprocket teeth and, 
in slipping in place again, give the machine a jerky motion 
as if some part of the machine were catching or striking some 



248 



AGRICULTURAL ENGINEERING 



other part. This action makes the difficulty hard to locate. 
It is easy to overcome by simply tightening the chain and by 
oiling. 

The elevator chain, the long chain which drives the ele- 
vator rollers, should not be run too tight, as it increases 
the draft and the wear of the parts. Machines are some- 
times greatly damaged in a short time by running this chain 
too tight. 

Adjustment. To make bundles of the proper size, the 
binder is provided with a clutch which is placed in gear by 
the trip when sufficient grain has been gathered by the 
packers to form a bundle. If the spring which holds the 
clutch pawl, or dog, in place be lost or broken, the clutch will 
not be positive in its action and will form undersized bundles. 
If larger or smaller bundles are desired, the bundle-sizer 
spring should be adjusted, and not the compress spring or 
the spring connected with the needle shaft. The latter spring 
is used to relieve the strain upon the parts, and should not be 
made too tight. 

Causes of Failure to Tie. The part of the binder which 
requires the most careful adjustment is the tying mechanism. 
Mention can only be made here of a few misadjustments and 
their symptoms. It is 
customary for those who 
practice binder experting 
to examine the band that 
comes from the machine 
when the machine fails 
to tie. Often the ends 
of the twine, whether 
frayed or cut off clean, 
the kinks in the twine, or the knot, if there should be one 
in one end of the band, will indicate at once the cause of 




Knotter. 
Fig. 154. 



Stripper 
The tyin 
modern binder. 



\ v 

Twine disk 

mechanism of a 



FARM MACHINERY 



249 



the failure to make a complete knot. The names of the 
various parts of the tying mechanism may be learned from 
the accompanying illustration. If the needle does not carry 
the twine over far enough, the twine disk, or cord holder, 
will grasp only one strand, and the knot will be tied only 

in one end of the cord, 
with the other extending 
back to the machine. 
This condition is shown 
in No. 1, Fig. 155, and 
may be caused occasion- 
ally by a straw interfer- 
ing with the placing of 
the twine. 

When the twine disk 
is too tight, the symp- 
toms will be much like 
those just described, ex- 
cept that one end of the 
band will be frayed (No. 
2,) indicating that it has 
been cut off by being 
pinched too tightly and 
that the spring should be loosened. If both ends are cut 
off irregularly, as shown in No. 3, it is quite a sure sign 
that the holder is too tight. 

If the knotter spring, which holds the finger down upon the 
knotter hook, is too loose and does not hold the ends of 
the twine while the knot is pulled over the hook forming the 
knot, the ends of the band will appear as shown in No. 4. 
The same kind of band is found when the knife cuts 
the twine too soon before the knotter finger has closed 
over it. 




Fig. 155. The ends of bands which have 
not been made into perfect knots. (After 
Steward in Trans. Am. Soc. A. E.) 



250 AGRICULTURAL ENGINEERING 

If the needle has become bent or the pitman which 
actuates it worn until the needle does not place the twine 
squarely over the notch in the twine . holder, a loose band 
will be produced as shown in No. 5, Fig. 155; that is, there 
will be a knot in one end, and the other end will be cut off 
squarely but without a kink in it. 

If the needle of the modern binder becomes slightly 
bent, it may be hammered back without fear of breakage. 

QUESTIONS 

1. Why is the grain binder an important machine? 

2. In what sizes are grain binders manufactured? 

3. What are the important features involved in the selection of the 
grain binder? 

4. To what use may the tongue truck be put? 

5. When may the machinery of the harvester be driven with a 
gasoline engine to good advantage? 

6. To what purpose should the binding mechanism of the harvester 
be adjusted? 

7. How should the elevator rollers, main and elevator chains be 
adjusted on a binder? 

8. What adjustment should be made to change the size of the 
bundles? 

9. Explain five causes for failure of the knotter to tie a knot. 



CHAPTER XXXVIII 
CORN HARVESTING MACHINES 

Sled Corn Cutter. These machines are arranged with 
stationary knives set at an angle on the edge of a platform 
and at such a height that the standing stalks will be cut off 
as they are grasped in the arms of the operator standing 
or sitting upon the platform. The machine is mounted 
either upon sled runners or upon low wheels and is drawn 
by one or two horses. When an armful of stalks has been 
collected, a stop is made and the corn laid in piles or is 
shocked at once. These sled cutters are often homemade 
and are constructed in a variety of shapes and forms. 

Several machines have been devised with arms and other 
mechanism to assist in gathering the stalks; but these ma- 
chines, although quite successful, have not come into extend- 
ed use, owing perhaps to 
the fact that, if a more 
expensive machine were 
desired than the simple ^ilfeftpsslA^ 

sled harvester, the corn {^^^^^^^^^^^ 
binder would be pur- 
chased. 

Fig-. 156. A sled corn harvester. 

It has been found 
that the average acreage harvested in a day by two men 
and one horse with a sled harvester was 4.67 acres, the 
amount ranging from 2 to 10 acres. This variation is un- 
doubtedly due largely to the weight and condition of the corn. 
The sled harvester cannot be used successfully in extremely 
heavy corn or in corn which does not stand upright. 




252 



AGRICULTURAL ENGINEERING 



The Corn Binder or Harvester. Because of the general 
introduction of the silo, the corn binder is used more than 
ever before. In filling the silo the corn must be cut rapidly, 
and besides it is much more conveniently handled when 
bound into bundles. When the corn is shocked, the use of 
the harvester will not show much economy over cutting by 
hand ; this, however, is disagreeable work, and the use of the 




A corn harvester of thc_ 



;rtical type at work. 



machine is to be commended because it does away with 
much of it. 

Results of an investigation of corn harvesting methods * show 
that the average acreage cut per day with a binder was 7.73 
acres. The average life of the corn harvester was 8.17 years, 
cutting on an average a total of 668.77 acres. The amount 
of twine used per acre was 2.44 pounds, and one man was 
able to shock the corn on 3.31 acres in one day. From this 

*Farmer's Bulletin 303, U. S. Dept. of Agriculture. 



FARM MACHINERY 253 

data the cost of harvesting and shocking an acre is made up 
in the following items: 

Cost of machine and interest on investment . . . $.29 per acre 

Driver and team 46 per acre 

Twine 305 per acre 

Shocking 448 per acre 

Total cost $ 1.503 per acre 

If a large acreage is harvested annually, the cost per acre 
will be much reduced. In modern siloing operations the 
corn is loaded directly upon wagons, and the cost of shock- 
ing, which is about one-third of the cost as given above, is 
not incurred. 

Types of Corn Binders. There are two general types 
of corn binders upon the market: those which bind the corn 
in an upright position, and those which convey the cut corn 
to a horizontal deck before binding. There is also an inter- 
mediate type in which the corn is neither vertical nor hori- 
zontal, but somewhere between the two, or inclined. Each 
of these types is well 
tried out and is success- ^^, — 

ful, and they differ but ^F 

little in the essentials of v ^^^f 

construction. Dividers -'^^^ 

on either side of the row • \ : -'' ~"'~- 

gather and lift the down Fig. 158. A corn harvester of the 
, it m • .,i i horizontal type. 

stalks. Chains with lugs 

extending across the opening between the dividers carry 
the stalks back to the binder proper. There are usually 
three pairs of these conveyor chains, one pair for the butts, 
one pair of main chains, and one pair for tall corn. 

At least one machine does not have the usual packer 
fount! on the others and on the grain binder. In this machine 



254 AGRICULTURAL ENGINEERING 

the conveyor chains are made to extend farther back, and 
during the time a bundle is being tied the lugs or fingers are 
allowed to fold back, not forcing the corn upon the needle. 
Three horses are usually used with the corn binder, though 
in heavy corn four horses, two teams in tandem, can be used 
to good advantage, and the extra power is much needed. 

The care and operation of the corn binder do not differ 
materially from that of the grain binder. The adjustment 
of the tying mechanism is just the same. The service 
demanded of the corn binder, however, is much more severe, 
and it does not have as long a life as the grain binder. 

The Corn Shocker. The corn shocker is an implement 
with cutting mechanism very similar to that of the corn 
binder, but a round, horizontal platform with a center pole 
is provided, and is made to revolve and collect the cut corn 
and form it into a shock. When a shock is formed, the ma- 
chine is stopped and the shock tied and then lifted from the 
platform and swung to the ground by means of a derrick and 
windlass. The fingers which extend out from the center 
pole are then allowed to drop, and the center pole is removed 
and returned to the machine. 

This machine has only about one-half the capacity of the 
corn binder, as much time is consumed in removing the 
shocks. Other disadvantages are, first, the shocks are small 
and do not stand well; and second, the fodder is not as con- 
venient to handle as when bound into bundles. In favor of 
it, it must be mentioned that it is a one-man machine, and 
there is a saving in the cost of twine. 

Corn Pickers. The successful corn picker is one of the 
most recent of agricultural machines, although inventors 
have been trying to invent a machine for field picking for 
nearly two-thirds of a century. The mechanical difficulties 
to be overcome and the lack of an imperative need for the 



FARM MACHINERY 255 

machine are the main reasons why this machine has not been 
perfected to the extent that it could be manufactured and 
sold in the usual way. 

Construction. As usually constructed, the corn picker, 
sometimes called the corn picker-husker, has dividers which 
straddle a row of standing stalks and gather them into an 
upright position similar to the action of a corn harvester. 
Then the stalks are run through rollers set at an incline and 
provided with spirals in such a way that the stalks are con- 
veyed back as fast as the machine is moved forward. These 
rollers pinch off the ears, which fall into a conveyor at one 



li 


few A ,Agw^ 


''*8fcK 


ifey^l 




1- 




P^^SWJ^^^^^ 


®!gS^S(py?^ 


Plflifliipps 








spls^'- 




rfbtir^ 



















Fig. 159. A corn picker-husker at work. 

side of the rollers and are carried to the husking rolls. These 
rolls revolve in pairs, and, by means of steel studs or husking 
pins set in the rolls, grasp the husks and pull them from the 
ears. The husked ears and the shelled corn are then 
elevated into a wagon drawn beside the machine. The 
better machines have a fan for blowing out the chaff and 
husks and saving all of the corn. 

The corn picker-husker is one of the heaviest of field 
machines, and under average conditions requires five large 
or six medium-large draft horses to draw it. A driver is 
required, and two men or boys with teams and wagons are 



256 



AGRICULTURAL ENGINEERING 



needed to haul away the corn as it is gathered and husked. 
An elevator for unloading the corn is quite an essential part 
of the complete outfit. 

There is naturally much difference of opinion in regard 
to the economy in the use of the corn picker-husker over 
hand picking. It is to be recognized that conditions vary 
greatly, and it is upon local conditions that its success will 




Pig. 160. A corn husker and shredder at work. 

depend. The machine, on account of its great weight, can- 
not well be used when the soil is wet. Again, the machine 
does not do its best work in corn that is lodged badly. It 
will not pick up any ears not attached to the stalks. 

Corn Huskers and Shredders. In many localities the 
husker and shredder is quite a popular machine, and it is 
right that it should be. As farming advances, methods 
utilizing the entire corn plant are sure to become more general. 

The modern husker and shredder consists in snapping 
rolls to remove the ears from the fodder as it is fed to the 



FARM MACHINERY 



'257 



machine, a shredder head to reduce the fodder to fine pala- 
table stock feed, husking rolls to remove the husks from the 
ears, an elevator to elevate the husked corn into a wagon, 
and an elevator or blower to convey the shredded fodder 




Fig. 161. A section of a corn husker and shredder. 

away from the machine. Most machines have devices for 
saving the shelled corn. Some of the larger machines have 
band cutters and self-feeders. 

The size of the husker is designated by the number of 
rolls. An eight-roll husker will husk from 25 to 80 bushels 
of corn per hour, and require from 16 to 20 horsepower. The 
cost of shredding varies from $2.50 to $6 per acre. 
QUESTIONS 

1. Describe the sled corn harvester. Is it practical? 

2. What are the principal items and the amount of each in the 
cost of harvesting corn with the corn harvester? 

3. Describe the two general types of corn harvester. 

4. Describe the construction of the corn shocker. 

5. Describe the construction of the corn picker-husker. 

6. Where may the picker-husker be used to the best advantage? 

7. What can you say of the economy of the husker and shredder? 

8. Describe the construction of the corn husker and shredder. 

9. How are the sizes of huskers and shredders designated, and 
what -is the capacity of the various sizes? 



CHAPTER XXXIX 

HAY-MAKING MACHINERY 

MOWERS 

The modern mower has become a standard machine, and 
the various makes differ in details only. Inventors have 
devised many styles of cutting machines, but all have given 
way to the reciprocating knife which acts between guards or 
fingers, giving a shear cut. 

Types. The center draft mower, with the cutting bar 
directly behind the team and in front of the driving wheels, 
is manufactured in a limited way. The main advantage of 
this type of machine seems to be that the team does not walk 
over the new-mown grass and tramp it into the stubble 
This advantage is offset by the convenience of the side cut 
machine, the type in general use. 

Size. Mowing machines may be secured in almost any 
size from the one-horse mower of 33^- or 4-foot cut to the 
8-foot-cut machine. The 4J^- and 5-foot cuts are known as 
the standard machines, and the 6-foot cut as the standard 
■wide-cut machine. The wide-cut machine is usually made 
somewhat heavier than the standard machines, yet they are 
adapted only to certain conditions where the service consists 
largely in straight meadow mowing. 

Construction of Mowers. The weight of a mower 
determines to some extent its driving power, but this is also 
increased by the design of the wheels and the distribution 
of the weight. The drive wheels should be high and have 
broad tires. The usual widths of tires are Q/i and 4 inches. 



FARM MACHINERY 



259 



It is best that the wheels be placed far apart, as this makes 
a better balanced machine as far as draft and driving power 
are concerned. 

The main shaft should be a smooth or "cold rolled" shaft 
throughout its entire length, and should be of liberal size. 
Roller bearings for the main shaft are desirable, as they not 
only reduce friction but also prevent any binding of the shaft 
in the frame and furnish a good reservoir for a supply of oil. 
It is well that the wheels be provided with a sufficient number 
of pawls to engage the axle ratchets without much lost 
motion. There should be little lost motion throughout 
the entire mechanism, as it is highly desirable to have the 
knife start as soon as the drivers and prevent the guards from 
becoming clogged. 

There is at the present time a considerable difference in 
the size of the gears used in mowers. Besides being strong 




Fig. 162. A modern mower at work. 



260 AGRICULTURAL ENGINEERING 

enough, these gears should be of liberal dimensions, especially 
in width, to resist wear. It is an advantage to have the gears 
so arranged that the thrust which exists between separate 
pairs of gears shall balance as far as possible. 

Due provision should be made to keep the gears well 
lubricated and well protected from dust. There is no good 
reason why the gears of mowers should not be arranged to 
run in oil, although this is not practiced. 

The small, fast-moving gear pinion is the first to wear 
out, and the construction of the mower should be such as 
to permit this pinion to be easily replaced. There is con- 
siderable end thrust on the crank shaft upon which the bevel 
gear pinion is placed, owing to the tendency for the gears to 
force themselves apart. This end thrust should be carefully 
provided for. Some of the best mowers upon the market 
are made with a ball-thrust bearing. Other mowers have 
hardened steel washers to take the wear, and in any case 
there should be means of adjusting for wear. 

The chain drive mower is used to some extent at the pres- 
ent time, but not as much as formerly. There are at least 
two disadvantages of the chain-drive mower, in which one 
pair of gears is replaced by a pair of sprokets and a chain or 
link belt; first, it is not as positive in action as the gears; and 
second, the chains do not seem to be as durable as the gears. 

Usually mowers have but two pairs of gears, but some 
mowers have three. No serious objections can be made to 
the latter. At least one make has two speeds for the knife, 
obtained by changing gears. The lower crank end of the 
crank shaft should have a bearing which will permit adjust- 
ment for wear. One of the most common methods of mak- 
ing this adjustment is to replace an interchangeable brass 
bush used as the bearing lining. In mowers there is an 
adjustable cap to the bearing, which may be adjusted by 



FARM MACHINERY 261 

means of the bolts which hold it in place and by the use of 
liners under the edges of the cap. 

It is to be expected that the severest wear will come upon 
the pitman. The pitman bearings are difficult to lubricate. 
A mower which does not provide for adjustment and replace- 
ment of the wearing parts of the pitman and crank is not 
modern. Owing to the difficulty of keeping adjustable parts 
tight, the crank pin box is usually made of solid metal, lined 
with brass or babbitt, and capable of being replaced at small 
expense. 

Provision is made in every modern mower for the replace- 
ment of the wearing parts of the cutting mechanism and for 
their adjustment to the fullest extent. This statement refers 
to the sickle or the sec- 
tions of it; the guards or 
their ledger plates, which 
provide one-half of the 
cutting edges; the clips 
which hold the knife 
over the ledger plates; 
and the wearing plates 
which support the rear edge of the sickle. All of these 
parts are subject to rapid wear, and even when made of the 
best materials they must be replaced several times during 
the life of the mower. It is not an uncommon matter to 
find that a mower has been discarded when it could be made 
practically as good as new by the replacement of parts whose 
cost is but a small part of the whole. 

The cutter bar of a mower should be carried as far as pos- 
sible upon the main truck, in order to reduce the draft due 
to dragging the bar. This is usually accomplished by suit- 
able linkage and springs which may be adjusted in such a 
manner as to carry all of the weight, except enough to keep 




A side-draft mower. 



262 



AGRICULTURAL ENGINEERING 



the cutter bar to the surface of the ground. A draft rod 
direct from the doubletrees to the cutter bar assists in lower- 
ing the draft, and is universally used on modern mowers. 
Adjustments of the Mower. The adjustments of the 
mower are of the greatest importance. First, the cutter bar 
should be in alignment, or should extend out to the side of 
the mower at right angles to the crank shaft. If not in per- 
fect alignment, the pitman will be cramped, increasing the 
wear, if not causing early breakage. There is sure to be 
more or less wear in the hinge joints of the cutter bar, and 




Fig. 164. 



An illustration showing the proper adjustment of the 
cutter bar. 



an adjustment must be made for this wear from time to time. 
The device for aligning the cutter bar differs in each type of 
mower, yet it is to be found in all good mowers. 

Secondly the knife should be made to register, or to travel 
equally over the guards at the ends of the stroke. Misadjust- 
ment in this respect is often the cause of failure to cut proper- 
ly. The method of adjustment varies with different mowers. 
In some the length of the pitman is changed; in others, the 
length of the drag bar. It is also true that many mowers 
do not offer a ready means of adjustment. 



FARM MACHINERY 263 

The sickle must be so adjusted under the clips that each 
section will form a shear cut with the ledger plates. The 
clips which hold the knife down are made of malleable iron or 
steel and are adjusted by bending down with a hammer. They 
must not be too tight; there should be a little clearance be- 
tween the knife and the ledger plates about equal to the 
thickness of ordinary paper. The guards must all be in line 
so that the above adjustment will be possible. Bent guards 
may be hammered back into line, as they are made of malle- 
able iron and are not easily broken. The alignment should 
be tested by sighting over the ledger plates. If the mower 
leaves streaks of long stubble, and the knife is in good con- 
dition, it is quite a sure indication that one or more of the 
guards have been bent out of line. The rear of the knife is 
supported by steel wearing plates which assist in keeping the 
points of the sections down over the guards. If these become 
worn until they no longer keep the knife in place, new ones 
must be put in, which may be done at small expense. 

The sickle should be kept sharp at all times. It is poor 
economy to use a dull knife, owing to the increase of wear 
upon the machine and the poor quality of work which is sure 
to be performed. All nicked or broken sections which can- 
not be sharpened should be replaced. If many of the sections 
are damaged, it is best to buy an entirely new knife. 

HAY RAKES 

The Sulky Rake. The sulky rake is made either to be 
dumped by hand or, by engaging a pawl on the tooth bar with 
a suitable ratchet on the wheels or axle, the machine is made 
self-dumping. The self-dump rake costs but little more 
than hand-dump and has the additional advantages. 

In selecting a sulky rake one need only consider the size 
and spacing' of teeth to suit the conditions to be met. The 



264 



AGRICULTURAL ENGINEERING 



teeth are made in two sizes,of ^le-inch and 3^-inch round steel, 
with one or two coils at the top to give more or less elasticity 
and with either pencil or chisel points. The teeth are spaced 
from 33^ to 5 inches apart. The heavier rakes are used for 




Pig. 165. A modern pelf-dump sulky rake at work. 



the heavier crops like alfalfa and sorghum. A rake should 
be so constructed as to be easily dumped and to thoroughly 
clean itself. 

Side-delivery Rakes. The side-delivery rake has much 
the same function as the tedder. Instead of merely turning 
the hay, however, the side-delivery rake has a revolving 
toothed cylinder acting in the opposite direction and set at 
such an angle as to deliver the hay to one side in a loose, 
fluffy windrow through which the air can circulate readily. 
Where the hay is light, it is put in good shape for the hay- 



FARM MACHINERY 



265 



loader. Where the hay is extremely light, two windrows 
may be thrown together. 

There is much difference in the mechanism of the side- 
delivery rakes. In general, there are two types: (1) the one- 
way rake, which has revolving forks to throw the hay to one 
side into a windrow; and (2) the reversible rake, which gathers 
the hay and conveys it onto an endless apron across the ma- 
chine and which may be driven in either direction. The first 
type is in more general use and is the cheaper machine. 




Fig. 166. A three-bar side-delivery rake at work. 



The fork machine, which is much like the tedder except 
that the forks are set in an oblique row and throw the hay 
forward and to one side, are preferred by many practical hay 
growers. Cylinder rakes, with teeth to catch the hay and 
roll it to one side, have the advantage of simplicity, but the 
rolling action given to the hay tends to make it into a close, 
compact, rope-like windrow through which the air does not 
circulate as readily as it might. Many of the fork machines 



266 AGRICULTURAL ENGINEERING 

are so arranged that the direction of the throw of the forks 
may be reversed and the rake used as a tedder. 

HAY LOADERS 

Where hay is stored in the barn, the modern hay loader 
is almost indispensable, as its use will pay for itself in the 
saving of labor in one or two seasons. In general, there are 
two types of hay loaders: the fork loader and the endless- 
apron or carrier loader. The first of these is of simpler con- 




Fig. 167. A fork hay loader at work. 

struction and is a machine that forces the hay well onto the 
load. 

The endless-apron loaders have one main advantage, and 
that is they do not agitate the hay severely and do not tend 
thereby to shake off the dry leaves. This advantage applies 
only in the handling of such crops as clover, alfalfa, and 
others whose leaves are easily shaken off. The end-less- 
apron machine does not force the hay onto the load readi- 
ly, for, when the hay is allowed to pile up at the end of the 
loader, the apron tends to drag the hay back. At least one 
loader has been brought out recently with the apron above 
the hay instead of below, in an attempt to overcome this 



FARM MACHINERY 



267 



difficulty. In selecting a loader, it would be well to see that 
it will pick up the hay cleanly, either from the swath or the 
windrow; will pass over the obstructions, and at the same time 
will not pick up old trash which may be on the surface of the 
ground. The loader is made largely of wood in the form of 
light strips, and for that reason should be carefully housed 
when not in use. 

' HAY TEDDERS 

Modern haying methods demand that the hay be cured as 
quickly as possible and that it shall not lie in the sun or dew 
to become bleached and stained. To do this, the drying of 
the plants must be hastened by the circulation of air through 
the loose hay. The leaves give up moisture to the air rapidly 
and draw upon the supply in the stem, and for this reason 
they should be prevented from drying up and falling off. 

The tedder is a machine arranged to pick the hay from 
the stubble where it has fallen from the mower and has been 
tramped down more or 
less by the team walking 
over it, and throw it into 
a light fluffy layer, 
through which the air 
may freely circulate. 

The size of the ted- 
der is designated by the 
number of forks which 
stir up the hay. The 8- and 10-fork machines are the 
sizes in general use. Most of the modern machines are 
made almost entirely of steel and, when carefully braced to 
give rigidity, are often preferred over the modern wooden- 
frame machines. Various combinations of gears, sprockets, 
and chains are used to drive the shaft giving motion to the 




A steel frame hay tedder. 



268 AGRICULTURAL ENGINEERING 

forks. One does not seem to have any special advantage over 
the other. The chain is the more flexible connection and 
costs less to repair than a broken gear when an accident 
occurs. 

MACHINES FOR FIELD STACKING 

In many localities where hay is one of the principal crops 
it is common practice to stack the hay in the field until a time 
when it may be disposed of either as loose hay or by baling 
and shipping. The factory-made machines used for field 
stacking are the sweep rake and the stacker. Each of these 
machines may be secured in a variety of styles. 

Sweep Rakes. The sweep rake may be a simple affair 
drawn over the stubble on skids or runners, or it may be 




Fig. 16R. A haying- scene showing' an over-shot stacker and sweep 
rakes at work. 

mounted upon wheels with elaborate mechanism for balanc- 
ing and raising the teeth. With some of these rakes the 
team is divided and one horse placed at either side, and with 
others the team is hitched to a tongue in the rear. The 
latter type, generally called the three-wheeled rake, is the 
more expensive and, although the team may be handled to 
better advantage, is difficult to guide. 



FARM MACHINERY 



269 



Stackers. Field hay stackers are divided into two classes, 
the plain overshot and the swinging stacker. The first has 
a row of teeth, corresponding to the teeth of the sweep rake, 
on the end of long arms hinged near the ground. The hay 
is left upon these teeth by backing away the sweep rake. By 
means of a rope and pulleys the teeth are raised to a vertical 
position and the load of hay allowed to slide back onto the 
stack. The objections of this type of stacker are that the 
hay must always be raised to a certain height regardless of 
the height of the stack, and the hay is always dropped in the 
same place on the stack, causing it to settle unevenly. 

The swinging stacker has a row of teeth on arms which 
may be raised to any height and locked in place by a brake 
engaging the rope; then the hay may be swung over the stack 
and dumped. As there is some choice as to where the load 
may be dumped, this style of stacker offers several advan- 
tages. It may also be used in loading hay onto the wagons. 

Homemade Stacker. Homemade field stacking ma- 




Fig. 170. A homemade field stacking outfit. 



270 AGRICULTURAL ENGINEERING 

chines are quite generally and successfully used. In addition 
to homemade models of the machine described, the hay fork 
can be successfully used to unload hay from a wagon onto a 
stack by the use of some sort of pole and pulley arrangement, 
as illustrated. Where a hay loader is available, this system 
of stacking offers advantages where the hay must be hauled 
some distance before stacking and where it is desired to build 
an especially high stack. Apparatus for doing field work 
with the hay fork may be purchased by those who do not 
care to make their own outfits. 

BARN HAY TOOLS 

Barn Equipment. The equipment for putting hay into 
barns consists essentially of forks or slings to hold the hay 
while being moved from the load, hay carriers with ropes and 
pulleys, and a track on which the carriers run. 

Forks. There are at least four types of hay forks in use, 
each of which is adapted to particular conditions. The 
single tine has spurs at the lower end which stand out at right 
angles to hold the hay. The hay is released by tripping the 
spurs, allowing them to turn downward. The single-harpoon 
fork is adapted to handle hay which hangs together, and is 
used where it is not desired to lift large quantities at one time. 

The double-harpoon fork is much similar to the single- 
harpoon fork except that two tines are provided instead of 
one. It may be secured in lengths from 25 to 35 inches. 

The derrick fork is used quite generally for handling alfal- 
fa in the field, but is adapted to a variety of conditions. It 
consists of a frame with four tines at right angles. It is 
very easy to insert into the hay. 

The grapple fork is used with short hay. It is provided 
with curved tines which swing toward each other like ice 
tongs, firmly gripping the hay. The tines are of various 



FARM MACHINERY 



271 



lengths to suit conditions, and vary from four to eight in 
number. The latter may be used in handling manure. 




Fig. 171. Types of hay forks in general use: 1 is the simple harpoon, 
2 the double harpoon, 3 the derrick fork, and 4 a four-tined grapple 
fork. 

Slings. Hay slings are webs made up of ropes and stick 
which are placed under and in the load of hay in such a way 
that the projecting ends may be brought together and the 
hay lying in the sling raised at one time. To release the 
hay, a spring catch is provided in the middle which allows 
the sling to part when tripped. 

Hay may be handled very quickly with slings; as much 
as 1000 pounds may be handled at one time if the equipmens 
is strong enough. Thus a wagon- 
load of hay may be removed in 
three or even two sling loads. To 
obviate the trouble of placing a 
sling within a load, a fork may be used for all but the last 
which may be taken up clean by a sling on the rack. 

Carriers. Carriers are made specially for forks, for slings, 
or for both. The latter kind is known as a combination car- 
rier. The size varies much with, the service. Light carriers 
are used with forks, and heavy carriers with double trucks 
are used with slings. Carriers which may be used in either 
direction from the stop in the track are called "two-way 




Fig. 172. A hay sling. 



272 



AGRICULTURAL ENGINEERING 




Fig. 173. 



carriers." If the lower part of the carrier can be turned 
about without removing from the track, the carrier is said 
to be reversible. 

Tracks. A rather large variety 
of steel and wooden tracks for car- 
riers is found upon the market. 
The wooden track is usually made 
of material four inches square. 
Steel tracks usually have a T or 
cross form of cross section. Often 
the latter is called "double- 
beaded" tracks. Various forms 
a hay carrier on a of switches are provided to convey 
hay in different directions from 
the point of loading. In round barns, pulleys are provided 
for carrying the rope around the circular track. 

QUESTIONS 

1. What is the standard cutting mechanism for mowers? 

2. Describe the two general types of mowers. 

3. Discuss some of the important features of construction. 

4. Why is a gear drive preferable to a chain drive? 

5. What parts of a mower are subject to excessive wear? 

6. Describe the two principal adjustments of a mower. 

7. Explain the points to consider in selecting a sulky rake. 

8. Explain the construction and use of the hay tedder. 

9. Describe two types of side-delivery rakes. 

10. Describe two types of ha}' loaders and give the merits of each. 

11. State the difference between overshot and swinging stackers. 

12. How may homemade outfits be arranged for field stacking? 

13. Describe the usual barn equipment for handling hay. 

14. Describe the construction of single- and double-harpoon, 
derrick, and grapple forks. 

15. What advantages do slings offer for unloading hay? 

16. Describe the different hay carriers. 

17. What kinds of hay carrier tracks are in general use? 



CHAPTER XL 
MACHINERY FOR CUTTING ENSILAGE 

Types of Cutters. There are two general types of ensilage 
cutters upon the market, and a third which is used to a limit- 
ed extent. These types may be best distinguished by the 
shape of the knives which are used. The first is the radial 
knife machine, the cutting knives of which are attached to the 
side of a large balance wheel. These knives make a shear 
cut with the cutting plate over which the fodder is fed. The 
second type may be designated as the twisted knife machine. 
The knives of this type, which are two to four in number, 
are attached to spiders on the main shaft, the knives being 
twisted to such an extent that a cylinder is formed. The 




An ensilage cutter of the radial-knife type equipped with 
blower at work. 



274 



AGRICULTURAL ENGINEERING 



fodder is fed directly into the cylinder. The third type of 
machine has a large number of narrow, hook-shaped knives 
arranged spirally around the main shaft, and may be desig- 
nated as the spiral knife machine. These cut as well as split 
the fodder as it is fed directly into the cylinder. 

Considering the relative merits of these various types of 
machines, the radial knife certainly has the advantage in 
simplicity. The fan blades are attached directly to the 
main cutting wheel, and this single rotating part forms the 
principal portion of the machine. All that is required in ad- 
dition is the feeding mechanism. The knives of this machine 
are more easily sharpened, as they are at least straight on 
the flat side. As the knives are often supported their entire 
length, they may be thinner, requiring less grinding in 
sharpening. 




175. Cutting heads of three types of ensilage cutters; 1 . 
radial knife, 2 the twisted knife, and 3 is the spiral knife. 



The twisted-knife machine is capable of very rigid con- 
struction and is safe against an explosion from overspeed. 
The spiral knives may be sharpened by filing without being 
removed from the machine. Most machines can be 



FARM MACHINERY 275 

furnished with interchangeable shredder knives for prepar- 
ing dry fodder. 

Elevating Mechanism. The pneumatic elevator, or 
blower, offers many advantages over the carrier elevator. 
It is easily adjusted to a silo of any height and is less likely 
than others to cause trouble. It requires considerably more 
power; in fact, without any definite information, it would 
seem that in many cases the blower requires at least one-half 
of the power supplied. If the engine is large and there is a 
surplus of power, the convenience of the blower may overbal- 
ance its extravagance in consuming power. The blower is 
more durable than the long chain elevators. It must be 
driven above a certain speed or sufficient blast will not be 
developed to elevate the silage. The blower pipe should 
always be set nearly vertical, or the silage will settle to one 
side of the pipe and not be elevated. 

Self-feed. The advantages of the self-feed are so great 
that every machine should be provided with one. This self- 
feed should be capable of having its speed adjusted to furnish 
a desired length of cut. The length of cut may be varied in 
some machines from }/i inch to \}/2 inches. Three-fourths 
of an inch is the popular length of cut among many feeders. 
In addition, the force feed should have a safety lever for 
instantly reversing the feed rolls and carrier in order to pre- 
vent accidents. 

Mounting. Ensilage cutters may be mounted either on 
skids or on trucks. The trucks add much to their conveni- 
ence, and should always be provided for the larger machines. 
In selecting the machine it is well to notice if the truck is of 
good substantial construction. There has been a tendency 
to use very small wheels, often of cast iron, which are very 
liable to break. 



276 



AGRICULTURAL ENGINEERING 



Construction. Although simplicity is desirable, care 
should be used in selecting a cutter to see that it is provided 
with a good strong main shaft, supported in good, long, 
babbitted bearings, and mounted in a substantial frame. 
The gearing should be strong enough to stand the variable 
load. The rolls should be flexible so as to grip the fodder 
firmly. The self-feed should be mounted either so as not to 
require folding when changing location, or so as to be easily 
folded. 

Selection of an Ensilage Cutter. The selection of an 
ensilage cutter is rather a difficult task, as these machines 

are of quite recent de- 
velopment and accurate 
information concerning 
the relative merits of the 
various types is not at 
hand. In deciding upon 
the size or capacity of 
cutter, several factors 
are involved. On the 
average it will be found 
that a cutter will require 
about one horsepower 
for each ton of capacity 
per hour. 

The gasoline engine, 
either portable or trac- 




Fig. 176. A twisted-knife ensilage cutter 
equipped with chain-carrier elevator. 



tion, 



makes a good 
power for driving the ensilage cutter. Its principal ad- 
vantage lies in the fact that it does not require constant 
attention. As many farmers have gasoline engines, the 
cutter must often be selected to suit the engine. The power 
to be used and the type of elevator are points to consider in 



FARM MACHINERY 277 

deciding the size. It is quite an advantage to have a machine 
large enough to take the bound bundles of fodder without 
cutting the bands. The smallest cutter equipped with a 
blower which will do this will require at least a 12-horse- 
power engine, and the engine must be liberally rated to work 
successfully. 

The common practice of using the steam traction engines 
of the neighborhood to furnish the power is to be commended ; 
first, because there is not an extra outlay of money for ma- 
chinery; and secondly, because the ordinary traction engine 
furnishes abundant power for even the largest cutters. 
When these large engines are used, it is best to buy a large 
cutter and rush the silo filling through. The corn harvester 
may be operated several days before the silo filling begins, 
in order that the fodder will be available as fast as needed. 

QUESTIONS 

1. Describe three types of knives for ensilage cutters, and state 
some of the advantages for each. 

2. What are the two types of elevators used for elevating ensilage? 

3. What is the usual length of cut of corn silage? 

4. Upon what kind of truck should the ensilage cutter be mounted? 

5. Describe some of the important constructional features of an 
ensilage cutter. 

6. What are some of the important factors to be considered in mak- 
ing a selection of an ensilage cutter? 



CHAPTER XLI 
THRESHING MACHINES 

Development. It is a big step of progress from the simple 
flail to the modern threshing machine. The use of the flail 
required the time of a man for the entire winter season to 
thresh even a very moderate crop of small grain which he had 
grown; whereas the modern machine is able to thresh hun- 
dreds or even thousands of bushels in a single day, delivering 
it cleaned and ready for market. 

The Operation of Threshing. The modern threshing ma- 
chine performs four quite distinct operations. The first is the 
process of threshing or shelling. This is accomplished when 
the unthreshed grain passes between the teeth of a revolving 
cylinder and those arranged in the concave. Second, the 
machine separates the straw from the grain and chaff. This 
operation is performed by the grate, the beater, the check 
board, and the straw rack. Third, the grain is separated 
from the chaff and dirt by screens in the shoe and by a blast 
from the fan. Fourth, by means of the stacker and the grain 
elevator or weigher, the straw is delivered to one point and 
the grain to another. 

Cylinder. The cylinder of a threshing machine is built 
up with heavy bars of steel mounted on disks or spiders, into 
which the teeth are fastened by thread ends and nuts or by 
keys. There are two sizes of cylinders in use, known as the 
small and the big cylinder. The big cylinder usually has 
about 20 bars. The speed at which a cylinder revolves will 
depend upon its size, but varies from about 800 revolutions 
for the big cylinder to 1100 revolutions for the smaller one. 



FARM MACHINERY 



279 



The Concave. The concave is made up of heavy bars 
into which teeth similar to cylinder teeth are fastened. It is 
located below the cylinder, and receives its name from its 
shape. The number of rows of teeth may vary according 
to the kind and condition of threshing, and may be varied 
by inserting removing bars. The concave may be adjusted 
by raising or lowering, the threshing effect being greater 
when the teeth are high and entered well into the teeth of 
the cylinder. 

The Grate. The grate consists of a number of parallel 
bars with open spaces between, placed directly beyond the 




Fig. 177. A section of s. modern threshing machine. 



concave teeth. A large part of the grain and chaff is allowed 
to pass through this grate before reaching the straw rack 
beyond. 

The beater is a webbed wheel beyond the cylinder, which 
beats the straw into a stream as it comes from the cylinder 
and enables it to be passed quickly over the straw rack. 

The Straw Rack. The straw rack is a vibrating rack 
which allows the stream of straw to pass over it but which 
sifts out the grain. There are many types of straw racks 
in use, and these vary in their construction and shaking 
motion. 



280 AGRICULTURAL ENGINEERING 

The Grain Pan or Conveyor. This is a solid removable 
bottom which extends from the cylinder back to the shoe 
and catches all of the grain coming from the grate and 
through the straw rack. 

The Shoe. The shoe is the frame which carries the 
sieves. In it the grain is separated from the chaff as the 
grain and chaff pass over the sieves and strike a blast of air 
from the fan. The sieves and the blast from the fan are sub- 
ject to adjustment, and upon their skillful manipulation 
depends largely the efficiency of the machine in cleaning the 
grain. 

The Self-Feeder and Band Cutter. The self-feeder is an 
attachment which receives bound bundles and elevates them 
to the throat of the cylinder, cuts the bands, and uniformly 
and evenly feeds the grain into the cylinder. 

Straw Stackers. Formerly the straw was taken care of 
by a carrier, which consisted of a frame over which an end- 
less web was drawn. Later this type of carrier was made 
to swing in different directions from the machine. Most 
machines of the present day are equipped with wind stack- 
ers, or blowers. These stackers have a fan which receives 
the straw from the straw rack and blows it to any part of 
the stack desired, reducing the amount of labor involved. 

The Weigher. The majority of modern machines are 
equipped with a weigher to measure the grain as it is delivered 
into the wagon or into bags. If the machine is simply pro- 
vided with an attachment to elevate the grain into the wagon 
box, the attachment for so doing is called the grain elevator. 

Size of Threshing Machines. There are usually two 
dimensions given to a threshing machine, or separator: the 
first is the length of the cylinder, and the second is the inside 
width of the machine, where the various separations of grain, 
straw, and chaff are brought about. The sizes vary from 



FARM MACHINERY 281 

18x22 inches to 44x66 inches, and 32x54 inches to 36x58 
inches. The 36x58-inch separator requires from 25 to 40 
actual horsepower to operate it successfully; and such a 
machine will thresh from 500 to 1000 bushels of wheat in 
a day, or about twice as much oats. 

Selection of a Threshing Machine. The choice of a 
threshing machine will depend largely upon the amount of 
grain to be threshed and also upon the method followed in 
threshing. In the United States, it is customary for the 
threshing to be done by experts who make a business of that 
kind of work. There are some localities where the individual 
farmer owns a threshing outfit, in which case the smaller 
sizes are used. Special machines are provided for special 
conditions. The threshing of beans and peas requires a 
special machine, as well as the threshing of clover. 

QUESTIONS 

1. Describe the four distinct operations performed by the modern 
threshing machine. 

2. Name the parts that perform each operation. 
3.' Describe the construction of the cylinder. 

4. Describe the concave and its adjustment. 

5. What is the main purpose of the grate? 

6. Where is the straw rack, and what work does it perform? 

7. What is the purpose of the grain pan? 

8. What function is performed by the shoe? 

9. Describe the construction and work of the self-feeder. 

10. What is the work of the weigher? 

11. How is the size of threshing machines designated? 

12. What are some of the important considerations involved in the 
selection of a threshing machine? 



CHAPTER XLII 
FANNING MILLS AND GRAIN GRADERS 

The Use of a Fanning Mill. The final selection of small 
grain seed must be made by mechanical methods. The 
plant breeder may well afford to make a hand selection of 
seeds, but the practical grower will find it quite impossible. 
There are from 700,000 to 1,000,000 wheat berries, about 
12,500,000 alfalfa seeds, and as many as 120,000,000 timothy 
seeds in a bushel. A bushel of corn contains about 100,000 
kernels; but only 3^8 to Yi bushel is required to plant one acre, 
which permits seed corn to be graded by hand more readily 
than other grains. However, it is more likely not to be done 
at all. 

Another vital requirement of good seed is that it shall not 
be mixed with any weed seeds which will foul the land and 
reduce the value of the crops. Also, in order that the modern 
seeding and planting machinery may do its work best, the 
seed should be free from trash and be uniform in size and 
weight. The first step to be taken in securing a uniform 
stand lies in cleaning and grading the seed. 

Often two or more grains are grown together or become 
accidently mixed, and the fanning mill is called upon to sepa- 
rate out the different kinds. To summarize, the functions 
of the fanning mill are : 

1. To clean grain, separating out trash and foul seeds. 

2. To grade grain, securing the best seed. 

3. To separate different kinds of grains. 

What the Fanning Mill Can Do. The fanning mill or 
grain grader can only grade, clean, or separate grains when 



FARM MACHINERY 



283 



there are certain physical differences between the grains to 
be separated. It is reasonable to think that no machine can 
separate two grains whose difference lies wholly in the name 
or color. The modern fanning mill is arranged to utilize 
several of the physical differences which may exist between 
grains. These differences may be, (1) difference in weight, 
(2) difference in size, (3) difference in shape. 

In addition, the roughness of the hull and the location of 
the heavy part of the seed may be used to some extent in 
making certain selec- 
tions or separations. A 
separation based upon 
a variance in weight is 
made by the use of a 
strong current of air. 
Some grain graders use 
this method almost 
entirely at the present 
time, and formerly all 
machines depended 
principally upon "fan- 

,, l.i Fig. 17S. A section of a fanning mill in 

mng tO dO the Sepa- which the blast does not strike the grain 

, . t , . until after it has passed through the sieves. 

rating, hence the name 

fanning mill. No doubt, the heavier grains are the most 
desirable for seed, and therefore fanning is the most im- 
portant feature of the modern fanning mill. 

Sieves, screens or riddles are used to grade the grain 
according to size. The grain first passes through a coarse 
screen, which takes out all the large particles, then over a 
finer sieve, or a combination of finer sieves, which lets the 
small grains and weed seeds through and which retains the 
larger seeds in one or more grades. 




284 



AGRICULTURAL ENGINEERING 



Striking examples of how use is made of differences in 
shape are found in the devices arranged to separate wheat 
from oats. In one device a riddle is provided with cells 
having a reverse turn. The short wheat grains are able to 
pass through this riddle, but the long oat kernels cannot. 
Another device consists of a cloth apron over the grain on 
the sieve, which maintains the grain in a thin layer and pre- 
vents the Ions; oat kernels 



from passing through, 
because the cloth pre- 
vents them from being 
upended. The wheat 
kernels, being shorter, 
pass through without 
difficulty. 

Certain grains like 
rye, for example, are 
heavier at one end of 
the berry than at the 
other, and if these grains 
are allowed to fall a certain distance they are quite apt to 
strike upon their heavy ends. This principle is made use 
of to a certain extent in some machines. 

Some of the weed seeds which are found in grass seed 
have a horny or burr-like hull which enables the seeds to 
adhere readily to any cloth with which they may come in 
contact. This characteristic of the seeds is made use of, in 
separating them out, by passing the seed in a thin stream 
over a felt roll. 

In general, there are two types of fanning machines: 
First, those in which the air blast is directed upon the grain 
as it passes over the sieves ; and second, those which use the 
air blast independent of the sieves and riddles. The first of 




Fig. 179. Another view of the type of 
machine shown in Fig. 17S. 



FARM MACHINERY 



285 



these is the older type. It has a rather large capacity for 
the amount of sieve surface provided, and when properly 
handled will do good work. The latter type, however, has 
the greater refinement and is capable of more careful selec- 
tions. 

The Selection of the Fanning Mill. There is a tendency 
among certain manufacturers to build a fanning mill of such 
light construction as to be neither durable nor able to with- 
stand hard service. These mills soon become rickety and loose 
in all of the joints. Therefore, in making a selection of a fan- 
ning mill, after deter- 
mining definitely that it 
will do the desired work, 
it should be carefully 
examined to see whether 
or not the frame and 
the body of the machine 
are made of good mate- 
rial and well put to- 
Fig. iso. a section of a fanning miii in get her. Wooden keys 

which the blast is directed below and i -i e 

through the sieves. and nails as means of 

fastening the joints 
should be guarded against. The shoe which carries the sieves 
should be well made to withstand the constant vibra- 
tion to which it is subjected, and conveniently arranged 
for the adjustment of the sieves. It is best that the length 
of the shaking stroke be subject to adjustment, as small 
seeds require a shorter stroke than large ones. 

Operation and Care. The air blast should be subject to 
regulation, either by changing the speed of the fan or by 
varying the volume of air supplied, which will permit it to 
be adapted to all conditions. Too little attention is often 
given to the construction of the sieves. The frames should 




286 AGRICULTURAL ENGINEERING 

be made of selected material and well put together, and the 
wire cloth should be firm and not easily distorted. Perfo- 
rated sieves are the best when made of zinc. They are 
the most accurate, as the perforations are quite sure to be of 
the same size. Their capacity, however, is less, and they 
prevent the passage of a blast of air through them. 

Sieves should be well cared for. A punctured or sagged 
sieve has its efficiency very much reduced. It would be well . 
to provide a rack for storing the sieves while not in use. 
The practice of piling them one upon the other is not at all 
to be commended. 

QUESTIONS 

1. Why is the fanning mill necessary in the grading of small-grain 
seed? 

2. What are the three functions of a fanning mill? 

3. Upon what three physical differences in seed does separation 
depend? 

4. What devices are used to separate by differences in weight? In 
size? In shape? 

5. Describe two types of fanning mills. 

6. What points of construction should be observed in making a 
selection of a fanning mill? 

7. Describe the adjustments of the blast and sieves in a fanning 
mill. 

8. Of what materials are the sieves made, and what is the ad- 
vantage of each? 

9. How should the sieves be cared for? 



CHAPTER XLIII 
PORTABLE FARM ELEVATORS 

The Portable Elevator. One of the most recent machines 
which has been developed to relieve the farmer of some of the 
hardest work to be found upon the farm is the portable ele- 
vator. Nothing is more tiring than shoveling corn into a 
crib after husking all day. The shoveling of wheat and 
other small grains into the granary at threshing time is like- 
wise laborious. The portable elevator not only does away 
with the hard work but also saves time and reduces the help 
required, both of which are to be obtained only at a premium 
during a rush season. A good elevator will do the work of 
from two to five men. 

Besides saving labor, time, and men, the portable elevator 
makes possible the construction of more economical cribs and 
granaries. These can be built much higher, thus increasing 
their capacity without increasing the cost of the roof or the 
foundation. With elevators, one is not compelled to build 
cribs or granaries on low foundations when wet ground 
makes it undesirable. 

In general, the portable elevator outfit consists of a dump- 
ing jack to lift the front wheels of the wagon and cause the 
load to flow to the rear ; a hopper into which the load is fed ; an 
inclined elevator with a chain carrier of nights or cups, which 
carries the grain to the highest point in the crib; a spout or 
conveyor to distribute the grain in the crib; and some source 
of power, either horse power or engine. 

The Lifting Jack. The lifting jack is made in two styles, 
the overhead and the lowdown. The former has a yoke or 



288 



AGRICULTURAL ENGINEERING 



frame under which the load is driven; the lifting is done with 
either ropes or chains running over pulleys above and back 
to a windlass below. The overhead type is the simpler of 
the two, but is a little inconvenient to move. Ropes are 
cheaper than chains, but are less durable. 

Nearly all of the various devices known for heavy lifting 
are used with fairly good success, such as the worm gear, the 
screw and nut, the hydraulic lift, the rack and pinion, and the 
windlass. The worm gear with windlass is one of the most 







Fig. 181. A portable fariT! elevator mounted on a truck and equipped 
with a folding hopper and a low-down dumping jack. 

common and most satisfactory. As a usual thing, a rough- 
cast worm gear is not a lasting part of a machine, and if port- 
able elevators are to be put in constant use no doubt greater 
refinement would be necessary at this point. 

The pump and cylinder, or the hydraulic jacks, are built 
with lifting chains extending down to the hubs of the front 
wheels, or with the cylinder placed directly under the front 
axle. In the latter type the piston rod has a yoke at the top 
which engages the axles and raises the entire front end of the 



FARM MACHINERY 289 

wagon as the oil, which is always the fluid used, is pumped 
into the cylinder below the piston. The hydraulic jack does 
not raise the load with an even motion, owing to the intermit- 
tent action of the pump. 

The screw and nut device acting upon the principle of the 
screw jack has one bad feature, and that is the lack of pro- 
tection of the screw from rust and dirt, as it must be bright 
and well lubricated at all times. The rack and pinion is a 
device used on at least two makes. This is connected to the 
front end of a platform at each corner, and the wagon is 
raised on the platform. This method obviates the difficulty 
of dumping wagons of long and short wheel bases. All jacks 
should have a quick return motion for returning the wagon 
to place. 

Wood and steel are used in the construction of the dump- 
ing jack. Owing to the fact that this implement is usually 
exposed more or less to the weather, during its season of use, 
at least, the steel construction is to be preferred. If the jack 
is to be moved from place to place often as conditions may 
require, it should be provided with a truck, which most manu- 
facturers will furnish at a slight extra cost. 

The Hopper and Elevator. The hopper, or elevator 
extension, is made so as to be raised to a vertical position or 
swung to one side so that the load may be driven into the jack 
or dump. In the first type, to assist in lifting the hopper, 
springs or a windlass should be, and usually are, provided. 
The carrier may be continuous through the hopper and the 
elevator, or a separate carrier or web may be provided for 
each. The first arrangement permits the hopper to be placed 
nearer the ground, but has a tendency to overload the chains 
of the carrier, which, in many cases, have too much to do for 
their strength. The low hopper is a decided advantage in 
unloading a low-wheeled wagon. 



290 



AGRICULTURAL ENGINEERING 



Cups and Drag Flights are used for conveying the grain 
up the carrier. The cups seem to be of the most desirable 
construction when the loaded weight is carried upon rollers. 




^ 



Fig. 1S2. A portable elevator equipped with an overhead dumping 
jack, swing hopper, and conveyor for distributing the grain. 

In the first place, these carriers will be the more durable, as 
the scraping action of the flights cannot help but produce 
an undue amount of wear, even when guides are provided 
to keep the flights free from the bottom of the elevator 
trough. In the second place, the cups will handle any kind 
of grain. 

The Derrick and the Conveyor. The derrick for holding 
the elevator at the proper angle is an important part of the 
machine. It should be so arranged that it may be erected 
quickly after being folded down, and should be provided with 
a powerful windlass. Cables are more durable than ropes, 
especially when greased occasionally to prevent rust. 

If the elevator is to be moved often, the elevator proper, 
the hopper and the derrick, should be mounted on a truck. 
Some of these trucks are very cheaply constructed ; yet, unless 
the elevator is to be moved far and often, an expensive truck 
is not needed. 



FARM MACHINERY 291 

All elevators can now be secured with conveyors which 
may be installed in the ridge of the crib or granary and which 
permit the grain to be discharged through a spout to any 
point. This is accomplished usually by having spouts to fit 
into removable sections of the bottom, or by shifting the 
whole conveyor on rollers. If the elevator is to have a perma- 
nent position in the building, the conveyor is almost essential. 
If the building is not too large, a better arrangement is to ele- 
vate the grain to the highest point possible, often to a cupola, 
and distribute it through a spout to the bins. The conveyor 
complicates the machine, and should be dispensed with if 
possible. 

If a two- or three-horsepower gasoline engine is at hand, 
it may conveniently be used to furnish power for the farm 
elevator; otherwise, a one-or two-horse sweep-power should 
be purchased. 

Selection. The selection of a portable elevator finally 
resolves itself into the choosing of a machine to suit the kind 
or kinds of grain to be elevated, and a careful inspection of 
the construction of the machines, as well as obtaining from 
the maker a guarantee insuring a satisfactory performance. 

QUESTIONS 

1. Why is the portable elevator an important machine for the farm? 

2. Describe the various mechanisms which are made use of in the 
lifting jack. 

3. Describe some important features of the construction of a 
portable elevator. 

4. Of what materials are portable elevators made? 

5. What are the relative merits of cups and nights? 

6. Describe the construction of the derrick. 

7. How are conveyors used in large cribs? 

8. What features should be given careful consideration in the 
selection of a portable elevator? 



CHAPTER XLIV 
MANURE SPREADERS 

The Utility of the Manure Spreader. The manure 
spreader will not only enable an operator to spread much 
more manure in a given time than it would be possible to do 
by hand with a fork, but better work is performed. A ma- 
nure spreader will thoroughly pulverize the manure and 
spread it in an even layer over the field. When hand 
spreading is practiced, the manure is not properly pulverized 
but is spread in large chunks or bunches, which "fire fang," 
thus causing a large part of the fertility to be lost. 

Construction. A manure spreader consists essentially 
of four parts: (1) A box with a flexible, movable bottom, 
called an apron; (2) gearing, or a mechanism to drive, at vari- 
ous speeds, the apron conveying the manure toward the 
beater; (3) a beater or toothed drum, which receives the 
manure from the apron, pulverizes it and spreads it evenly 
behind the machine ; and (4) a truck to carry the box and to 
enable the power to drive the machine. 




Fig. 1S3. A modern manure spreader at work. 



V 



FARM MACHINERY 293 

Types. There are two general types of manure spreaders, 
classified by the construction of the aprons. The endless 
apron passes over rollers or reels at each end of the box, and 
is arranged to be driven in one direction only. As soon as 
a load is discharged, the apron is stopped and is ready to 
receive another load. This type of apron is more likely 
to become fouled by manure passing through the upper side 
and lodging in the inside of the apron below. In freezing 
weather this manure on the inside becomes frozen, and is 
quite likely to cause breakage. The slats are placed quite 
close, however, and in many instances these troubles are 
not experienced at all. One maker of the endless apron 
spreader has the slats of the apron hinged so that while on 
the under side they hang vertically, preventing the manure 
which comes through the upper side from lodging below. 
Again, another style of endless apron does not have slats 
over much more than half of its length, and in this way 
prevents fouling by leaving the under side open. In other 
instances the apron proper is replaced with a drag chain 
which drags the manure over the tight floor of the box. 
Usually this type of apron, or conveyor, to be more correct; 
is used only with the small-sized machines, as the amount 
of power required to drag the load is much greater than to 
move it on an apron supported by rollers. 

The return apron, after discharging its load, is brought 
back into position again by a reverse motion. The return- 
apron spreader has more mechanism than the endless apron, 
on account of this return motion. The front end board is 
attached to the apron and draws the load well into the beater 
at the finish. 

A few endless-apron spreaders have a front end board 
that moves with the load, and which, after the load has been 
spread, is brought forward again by hand. 



294 



AGRICULTURAL ENGINEERING 



Main Drive. The main drive from the rear wheels, which 
furnish the power to the beater, is an important part of the 
spreader. Gears and chains are used to transmit the power. 



SULM^Mi 




Fig. 184. 



One type of drivini 
to the beater. 



Chains offer an advan- 
tage in case of breakage, 
as a chain can be easily 
and cheaply repaired. 
Breakage is more likely 
to occur when starting 
the machine than at any 
other time. To prevent 
the beater from throwing 
lechanism over a big bunch of ma- 
nure when put in motion, 
a rear end board is provided, which is raised when the ma- 
chine is started. The beater may also be moved away from the 
manure when going into gear, thus overcoming this difficulty. 
The Beater. The beater for pulverizing the manure is 
made up of bars of teeth which revolve at a relatively high 
speed against the manure fed to it by the apron. It 
should be constructed of durable material; wood bars are 
generally used to hold the teeth, but beaters made entirely 
of steel are used on a few machines. The size does not seem 
to be so important so long as the teeth are given the proper 
speed to pulverize the manure well. The height of the beater 
in reference to the apron is important, for if placed too low it 
tends to drag the manure over without pulverizing it. Beaters 
placed high are quite apt to cause the machine to be of 
heavy draft. 

The teeth of some beaters are placed in diagonal rows 
around the beater, which tends to comb the manure from the 
center, where the load is the deepest, toward the outside, 
giving a more even distribution. 



FARM MA CHINERY 295 

Several devices have been invented to spread the manure 
over a wider swath than the width of the machine. Under 
average conditions the machine requires all the power avail- 
able to properly pulverize the manure needed to cover the 
width of the machine. 

Retarding Rake. To prevent the manure from being 
thrown over in large bunches, a retarding rake is provided in 
front of the beater. In some machines this is given a vibra- 
ting motion which tends to level the load. 

Apron Drives. There are at least two mechanisms in use 
for moving the apron at various rates of speed toward the 
beater. One is the worm drive, in connection with a face 
wheel and pinion to give variable speeds. This device gives 
a uniform motion and is positive, 
preventing the apron from mov- 
ing too fast, as when the spreader 
is ascending a hill and the load 
has a tendency to slide back into 
the beater. As a general rule, a 
worm gear when used in this 
way does not wear well. Some „. „ or ^ . t A . ■ 

J Fig. 185. One type of driving 

Of the latest machines have this mechanism to the apron. 

gear inclosed so as to run in oil. 

The ratchet drive is simple but does not give a steady 
motion. It is very easy to obtain a wide range of speed with 
this device. The ratchet acts only in one direction, and in 
hilly localities the apron must be provided with a brake to 
prevent it from feeding too fast in ascending a hill. 

The return motion for return-apron spreaders is usually 
separate from the feed, and safety devices are provided to 
prevent the possibility of having both motions in gear at the 
same time. 




296 AGRICULTURAL ENGINEERING 

The Truck. The truck of the manure spreader is impor- 
tant, as it is often the first part to wear out. Steel wheels 
are quite generally used now, and in dry climates they are 
preferable to wooden ones. It is also important that the 
frame of the truck be constructed of durable material, which 
should be well braced and trussed. Maple is to be preferred 
to pine for the frame. 

Capacity. The capacity or size of a manure spreader is 
designated in bushels, but this seems to be an arbitrary unit 
at the present time. As now rated the capacity would be 
more nearly represented by cubic feet. 

Low-down Spreaders. The latest development in ma- 
nure spreaders is the low-down spreader, which is built so that 

the top of the bed is very 
low. It is obvious that 
this type of construction 
reduces the labor in load- 
ing by the fork, and it 
is also more convenient 
for filling from a litter 
carrier. 

A low-down spreader. 

Wagon-box Spreader. 

The wagon-box spreader is a machine designed to be placed 
on the rear of an ordinary farm wagon or farm truck. 
The power is transmitted by sprockets clamped to the rear 
wheels. This machine is small, light, and cheap; it furnishes 
an opportunity to use the truck for other purposes. The 
manure spreader, however, is a machine in such constant 
use as to demand a truck of its own. 

QUESTIONS 

1. Why is machine spreading of manure to be preferred to hand 
spreading? 




FARM MA CHIXER Y 297 

2. What are the four essential parts of a manure spreader? 

3. Describe the two types of aprons in use, and what are the 
advantages of each? 

4. What is a drag chain conveyor? 

5. What is the use of a front end board? 

6. Describe two types of main drive. 

7. How should the beater be constructed? 

8. What is the purpose of the rear end board? 

9. State the purpose of the retarding rake. 

10. Describe two systems of apron drives and give the merits ol 
each. 

11. What points should be observed in selecting a truck? 

12. How is the size or capacity of a manure spreader designated? 

13. What is the advantage of a low-down spreader? 

14. Describe the wagon-box spreader. 



CHAPTER XLV 



FEED MILLS AND CORN SHELLERS 

Feed Mills." The work of the feed mill is the reduction 
of grain to meal. In some machines it is necessary that this 
process be accomplished by two stages, especially if ear corn 
is to be ground. The corn first passes between a set of crush- 
ing rollers and then through the main grinding mechanism of 
grinding plates or buhrstones. Feed mills differ most in the 
construction of the grinding plates or buhrstones. 

Grinding Plates. Buhrstones are used where a very fine 
meal, such as is required for table purposes, is desired. Most 
feed mills used for grinding feed for live stock have chilled- 
iron grinding plates. These are hard, they wear well, and 
can be easily replaced at a small expense when worn out. 
These grinding plates are made in a variety of shapes, al- 
though the flat or disk shape is the more common. They 
are sometimes made cone shaped. 
Roller mills are used to some 
extent for grinding feed for live 
stock. These rollers are generally 
made smooth and depend upon 
the crushing of the grain to reduce 
it. The roller may have a milled 
surface and revolve against the fixed 
part or grinding plate. 

The Power Mill. Power mills 
are usually arranged to be driven 
by a belt or a tumbling rod. A 

1S7. A belt-driven feed it i i • -in 1 

mm. balance wheel is considered a de- 




FARM MACHINERY 



299 




sirable feature of a power mill, as it enables the machine 
to run more steadily. When two kinds of grain are to 
be ground together, a divided hopper is quite an advan- 
tage. Most feed mills are provided 
with safety devices which release the 
grinding plates and prevent damage 
should something hard be fed into the 
mill, or with quick releases which will v Zt%k It ^hmeTc'ast 
enable the operator to separate the lron ' 
grinding plates quickly. Such mills should be provided 
with an elevator or sacking attachment to assist in caring 
for the ground feed as it is prepared. 

Selection of a Mill. The selection consists primarily in 
securing a machine constructed with bearings which will run 
well and can be adjusted easily, and with grinding plates 
which can be easily replaced and adjusted. The capacity 
of feed mills and the amount of feed which the mill will grind 
in a given time depend upon the condition of the grain and 
the fineness of grinding. Furthermore, the capacity of the 
feed mill usually becomes less and less from the time the 
grinding plates are new until they are replaced. A good feed 
mill should grind five bushels of corn or two to three bushels 

of oats for each horse- 
power used. 

CORN SHELLERS 
There are two general 
types of corn shellers on 
the market, one is known 
as the spring or picker 
sheller and the other as 
the cylinder sheller. 

The Spring or Picker 
Sheller. The spring or 




Fig-. 1S9. A small two-hoe picker- 
wheel sheller equipped with self-feeder, 
cob carrier, and elevator. 



300 



AGRICULTURAL ENGINEERING 



picker sheller is the one in more general use and is adapted 
to smaller machines. The shelling mechanism consists of the 
picker wheels, the bevel runner, and the rag iron mounted on 
a spring. These three form a triangular open chute through 
which the ears of corn are fed. The rag iron is adjustable to 
adapt the machine to large or small ears. On large machines 
a self-feeder is provided, which arranges the ears endwise 
and feeds them into the sheller. In shelling large cribs of 
corn, extension feeders are provided to convey the corn from 
the crib to the self-feeder. 

Cylinder Shellers. The cylinder sheller consists of a 
beater wheel within a cylinder made up of parallel steel bars. 




Fig. 190. A section of a picker-wheel sheller. 

The corn is fed into one end of the cylinder, and, as the ears 
pass along, the corn is shelled by being crushed against the 
cylinder by the revolving beater wheel. Cylinder shellers 
break up the cobs more than picker shellers. 

Separating Device. All power shellers should be pro- 
vided with a shoe and sieve, and a fan to blow out the chaff 
and dust. Sometimes a vibrating rack or raddle is substi- 
tuted for the sieve. After being cleaned, the corn is elevated 



FARM MACHINERY 



301 



into the wagon box, and the cobs are conveyed is another 
direction by a cob carrier. 

Capacity. The size of a picker sheller is designated by 
the number of "holes," or sets of shelling wheels, and these 
vary from the one-hole hand machine to power machines 
with as many as eight holes. The average size is the four- 
hole sheller, which will usually shell from 100 to 200 bushels 
an hour; the six-hole will shell from 200 to 300 bushels an 




191. A section of a cylinder sheller. 



hour; and the eight-hole, 500 to 600 bushels. The cylinder 
sheller is made in the large sizes only, some having a capacity 
of as much as 800 bushels per hour. The power required for 
operating corn shellers varies with the size. The four-hole 
power shellers with all attachments will usually require about 
eight horsepower. The power required to operate cylinder 
shellers will vary with the size, style, and the manufacturer's 
number. 

QUESTIONS 

1. What is the work of the feed mill? 

2. Describe the various types of grinding plates used in feed mills. 



302 AGRICULTURAL ENGINEERING 

3. How is the grain reduced by means of rollers? 

4. What are some of the attachments of a feed grinder? 

5. Wha,t safety device is usually provided? 

6. What are some of the important features to be considered in 
the selection of a feed mill? 

7. How much feed may be ground per horsepower per hour? 

8. What are the two distinct types of corn shellers in use? 

9. Describe the shelling mechanism of the spring or picker sheller. 

10. Describe the cylinder sheller. 

11. Describe some of the attachments provided for a sheller. 

12. What is the capacity of various sizes of corn shelters? 

13. How much power is required? 



CHAPTER XLVI 
SPRAYING MACHINERY 

Successful fruit growing at the present time depends 
largely upon an intelligent and skillful fight against fungous 
diseases and injurious insects. Even the small orchardist 
finds that he cannot afford to overlook the spraying of his 
trees at the proper time. Field spraying has been introduced 
recently to exterminate also certain noxious weeds, such 
as mustard in grain fields. 

Hand Sprayers. There are a multitude of hand sprayers 
or syringes upon the market, but it is not the purpose to take 
up these. The use of these appliances is limited to the 
greenhouse or to shrubbery. The bucket sprayer is one step 
in advance, and may be used quite successfully on a few trees 
if they are not too large. Most of these sprayers throw the 
spraying solution up above the trees in such a way that the 
spray falls upon the foliage. In many cases this is undesir- 
able. The spray should be driven into the foliage in such 
a way that the underside of the leaves and the inside of the 
flowers will be reached by the spray solution. A liberal use 
of brass in the construction of the small sprayers is one of the 
features which indicates quality. 

The Barrel Spray Pump. The smallest and cheapest 
machine for spraying small orchards is the barrel pump. 
Where a few trees are to be sprayed, this is undoubtedly the 
machine that should be selected. 

The pump may be mounted on either the end or the side 
of the barrel. If located on the side, the pump will more 
nearly remove all of the solution from the barrel, as the 



304 



AGRICULTURAL ENGINEERING 



suction pipe extends to the lowest point. It is an advan- 
tage to have the pump low, as the handle is then in a more 
convenient position. If the holes cut for the pump and the 
filling funnels are not too large, a barrel in a horizontal posi- 
tion, with two heads, is more rigid and less likely to go to 
pieces when empty for a time. 

All the working parts that come in contact with the 

spray solution should be brass, as it is the only metal in use 

*<$& which will resist the corrosive 

action of some of the solutions 

in common use. The valves 

should be either ball or poppet, 

with removable seats. The ball 

valve seat may be replaced for 

a nominal sum, making this 

part of the pump as good as 

new. Brass poppet or disk 

valves may be renewed in the 

same manner, or they may be 

repaired by grinding. Fine 

Fig. 102. a good type of barrel emery with oil is placed be- 

ppray pump with dash agitator. ' ' 

Note the plunger cylinder and the tween the valve and its seat 

large air chamber. 

and the valve turned back and 
forth in a rotative manner until the surfaces are ground 
to a perfect fit. 

The plunger type of cylinder has many advantages. It is 
of easy access for repairs, and it is easy to determine whether 
or not the plunger is leaking. The packing is often placed 
between two disks, which cause the packing to expand as 
they are screwed together on the plunger rod. The pump 
with the stuffing box and the inside plunger is to be guarded 
against. Of course, double-acting pumps must have stuff- 




FARM MACHINERY 305 

ing boxes, but it is doubtful if the double-acting pump 
offers much advantage. If the pump cylinder is not sub- 
merged, it should be placed near the surface of the liquid 
in the barrel. The air chamber should be large, as it 
equalizes the pressure and makes the pump easier to 
operate. 

Every barrel pump should be provided with an agitator 
to keep the heavy spray mixtures stirred. The double-paddle 
type is undoubtedly the most efficient type now in use, but 
the dash agitator is in more common use and is quite efficient. 

Field Sprayers. Field sprayers differ largely in their con- 
struction, as they are designed for spraying different crops. 
First, in selecting such a machine, consideration should be 
given to the truck and the tank. These should be of sub- 
stantial and durable construction. The gearing driving the 
pump should be of substantial construction; gears, chains 
and sprockets, cranks, cams, and eccentrics are used in this 
connection, but it has not been demonstrated that any one 
particular combination has any special advantages over any 
other. The size of the pump must vary with the number 
and kind of nozzles to be supplied. Some of the field ma- 
chines used for spraying mustard and other weeds are of 
large capacity, supplying as many as twelve nozzles and 
covering a width of twenty feet. 

Convenience is one feature of great importance in the 
field sprayer. The machine should be easy to fill and to 
control. The position of the nozzles should be susceptible 
of any adjustment which may be necessary. The pump and 
driving mechanism should be of ready access for adjustment 
or repairs. 

The Power Sprayer. Where there is a considerable 
amount of orchard spraying to be done, the power sprayer 
will be found the most economical and efficient. Man power 



306 



AGRICULTURAL ENGINEERING 



is expensive, and it is well-nigh impossible to maintain suf- 
ficient high pressure by hand to do the best kind of spraying. 
Power. Steam engines have been used to some extent 
as a source of power for spray pumps, or steam has been used 
directly in direct-acting steam pumps. The great weight 
of the steam boiler has caused its replacement by the gasoline 
engine almost entirely. The gasoline engine is cheap in first 




A power sprayer. 



cost, cheap in operation, and is light, which make it especi- 
ally adapted to the purpose. 

The first requisite of a gasoline engine for a spraying out- 
fit is reliability. It must operate under adverse conditions, 
and there should be sufficient capacity to operate continu- 
ously without overheating. 

Pumps. The plunger pump with outside packing of the 
duplex or triplex type is now being generally used in the 



FARM MACHINERY 307 

better grades of spraying outfits. Since these are more 
accessible than the usual double-acting pump, they are more 
easily packed. The triplex pump furnishes a more even 
flow of liquid, but introduces extra parts and is undoubtedly 
of more expensive construction. The air chamber should 
be designed to suit the kind of pump used. 

The Drive. The drive from the engine to the pump is 
either a gear or a combination of gear and belt. If a gear 
is used, it is highly essential that the pump and the engine 
be mounted upon the same base, thus insuring more rigid 
construction. 

Agitator. The most efficient type of agitator for power 
sprayers is the propeller type. The small screw propellers 
in the tank cause the liquid to circulate rapidly over and 
over in the tank, carrying the heavy particles in the spray 
mixture to the surface. Dash or paddle agitators do not 
produce this action. 

The relief valve is one of the most sensitive parts of the 
modern sprayer. Its purpose is to regulate the pressure, 
allowing the surplus liquid pumped to return to the tank. 
The regulator valve, used in place of the relief valve and 
which cuts off the flow to the .pump after a certain pressure 
has been reached, is a commendable device, as it relieves the 
engine of part of its load and thus reduces the wear upon it. 

Tank and Truck. The tank and truck should be given 
careful consideration. In general, the machine which may 
be moved about the most easily is the most desirable. For 
this reason, lightness is one of the requisites of a good spraying 
rig. As the sprayer must be hauled over soft ground, high 
wheels with wide tires foi the truck are desirable. The con- 
struction should permit turning in very limited space. 

Accessories. The hose, extension rods, nozzles, cut-offs, 
and other accessories are the things with which the operator 



308 



AGRICULTURAL ENGINEERING 





19 1. The Bordeaux nozzle and 
cluster of four Vermorel nozzles. 



must work directly, and often efficient work will depend upon 
their quality. Cheap hose is poor economy. The extensions 
are best when made of bamboo with a brass tube on the 
inside to carry the liquid. Good substantial ferrules should 
be provided at the ends to relieve the thin brass tube of all 
strains due to dragging a length of the hose about. A con- 
venient and perfectly 
tight shut-off adds 
much to the pleasure 
of operation. 

There are two gen- 
eral types of nozzles in 
use: the Bordeaux 
nozzles, in which a 
spray is produced by directing the jet against the edge of 
the orifice; and the Vermorel, which has an eddy chamber 
directly below the orifice. In the latter, the liquid is given 
a whirling motion, causing it to be driven from the orifice 
in a cone-shaped spray. 

The Bordeaux nozzle produces a fan-shaped spray, which 
has considerably more force than the spray from the Vermorel 
nozzle. The latter is generally known as the fine-spray 
nozzle; by making the eddy chamber and the orifice large^ 
the spray has much more force and capacity. 

QUESTIONS 

1. What is spraying machinery used for? 

2. State some of the important construction features of sprayers. 

3. What are field sprayers used for? 

4. What adjustment should be provided for a field sprayer? 

5. What power is most generally used for power sprayers? ' 

6. Describe the different types of spray pumps of power sprayers. 

7. In what different ways is the pump driven? 

8. What types of agitators are used for power sprayers? 

9. Describe two types of spray nozzles. 



CHAPTER XLVII 
THE CARE AND REPAIR OF FARM MACHINERY 

The efficiency of modern farm operations depends pri- 
marily upon the successful and judicious use of improved 
farm machinery. This fact is generally recognized. No 
other country uses as much machinery as the United 
States. The Census of 1910 showed that the American 
farmer was annually buying 149,318,544 dollars' worth 
of farm machinery. This amount was equal to over 3.3 per 
cent of $4,499,319,838, the value of the crops raised. It is 
only possible at this time to make a rough estimate of what 
percentage of the farmers' profits 3.3 per cent of the value 
of crops is. Perhaps 20 to 30 per cent would not be too large. 
Any feature of farm management which absorbs 20 to 30 per 
cent of the profits is well entitled to earnest consideration. 

Much has been written from time to time about the care- 
lessness of the American farmer in caring for his machinery. 
Various estimates have been made of the life and deprecia- 
tion of the more important farm machines. Perhaps, in 
many cases, these estimates have been too low; but there 
is little doubt in the mind of the person who makes only a 
casual investigation, that average life of most farm machines 
is much less than it ought to be. An investigation on several 
farms in Minnesota* indicates the average depreciation of 
farm machines to be 7.3 per cent annually. It is to be noted 
that this represents the most favorable conditions, since the 
farms investigated were well managed. 

The care or management of farm machinery readily 

*Bulletin 117, Minn. Agricultural Experiment Station. 



310 AGRICULTURAL ENGINEERING 

resolves itself into three heads : repairing, housing, and paint- 
ing. Of these, the repair item is perhaps the most important. 
The greater part of the average farm machine is not subject 
to wear, and, if not broken, ought to last indefinitely. Con- 
sidering the modern gang plow, except the share, moldboard, 
wheelboxes, and axles, there are comparatively few parts sub- 
ject to wear. All of these should be either adjustable or renew- 
able at a small expense. The main parts of the plow, the 
parts which absorb the greater part of the cost of making, 
as the frame and the beam, ought to last indefinitely. Bail 
boxes and wheel boxes are easily and cheaply replaced, and, 
when renewed, make these parts of the plow as good as when 
it left the factory. 

Repairing. To repair farm machinery successfully some 
system must be used, and the early spring is the time of 
year to give thought to this. No doubt many a machine 
is taken from storage in the spring, or whenever the machine 
is needed, and the owner finds that he has forgotten to 
order certain repairs, which, he remembers, were needed at 
the close of the previous season. When he proceeds to order 
these repairs from his agent, he finds that others have done 
likewise; and the agent, the jobber, and the manufacturer 
are rushed with orders. There are always delays and short- 
ages, which often result in the purchase of new machines, 
as those familiar with the farm industry are aware. If the 
necessary parts had been ordered months before, they would 
have been secured without fail, and they could have been 
put in place on the machine and the machine adjusted and 
made ready for work. Repairs for the older machines are 
not carried in stock except at the factory, and for this reason 
plenty of time must be allowed for filling orders. Again, it 
would be a decided advantage to repair the machinery at the 
time of the year when work is less pressing. On most farms 



FARM MACHINERY 311 

some of the winter months offer a good opportunity to do 
miscellaneous work of this character. 

System of Repairs. A definite sytem has proven to be 
very useful in keeping farm machinery in repair. As each 
machine finishes its work for the season and is placed in the 
implement house, a tag with a string is taken from a conveni- 
ent place and a record is made of the repairs that the machine 
needs for the next year. It is much easier to make this record 
at that time than later, as everything is fresh in mind. An 
inspection of this tag at any time will show just what the 
machine needs in the way of repairs. Before the busy sea- 
son all the machinery should be gone over systematically, 
and the needed parts sent for or repaired in the home shop. 

More emphasis should be placed upon the matter of 
systematic repairing than upon any other phase of the care 
of farm machinery. 

Housing. I't may be demonstrated that rust is more 
destructive than wear. A striking example of this is found 
in the harvester. Its average life extends over a certain term 
of years, largely independent of whether it harvests 40 or 
200 acres of grain each year. Again, we find in machine 
shops and factories machinery which has lasted as long as 
the harvester and which, instead of being in operation a few 
days in a year, is in operation ten hours or more day in and 
day out without rest. 

Wooden parts are affected more by exposure to the weather 
than metal parts, but both are materially injured. Not 
only is the life of machinery shortened, but its efficiency, the 
quality of its work, is lowered by not being carefully protected 
from the weather. The average farm requires about $1000 
worth of machinery. This may be nicely housed in a build- 
ing costing $200, an investment that will pay good divi- 
dends in protecting and prolonging the life of the machinery. 



312 AGRICULTURAL ENGINEERING 

The construction of the implement house will be discussed 
in a later chapter. 

Painting. Painting is simply providing each implement 
with a house of its own. Wooden parts deteriorate rapidly 
when moisture is allowed to penetrate the surface. Wood 
decays and warps, rendering it weak and useless for the pur- 
pose for which it is used. Unprotected iron or steel when 
exposed to the weather unites with oxygen of the air, or 
rusts, gradually giving up its strength. Steel bridges decay 
in this manner so rapidly that they must be replaced after 
a term of years. To protect these metals, their surfaces are 
coated with paint to keep out the moisture and air. Rail- 
road companies and large corporations find it profitable to 
keep their steel bridges and stuctural work well painted. 

Perhaps there is no better paint for implements, not tak- 
ing into account a personal dislike which some have for the 
color, than red lead and linseed oil. This paint will adhere 
well to clean surfaces of wood and iron, and is affected about 
as little by the weather as anything that can be used. 

Besides prolonging the life of the machines themselves, 
a machine dressed in a good coat of paint commands more 
respect and is looked upon as being a better machine. The 
author can recall specific instances where a coat of paint 
has increased the selling price of machinery fifty per cent 
or more. 

QUESTIONS 

1$ How much does the American farmer spend annually for farm 
machinery? 

2. What percentage is this of his gross and of his net income? 

3. What is the average depreciation of farm machinery? 

4. Explain why the repair of farm machinery is so important. 

5. Describe a system of keeping all farm machinery in good repair. 
{3. Why is the housing of farm machinery so important? 

7. Give several reasons why machinery should be" kept painted. 



PART SIX— FARM MOTORS 



CHAPTER XL VIII 
ELEMENTARY PRINCIPLES AND DEFINITIONS 

Farm Motors. Farm motors as discussed in this text 
include machines which furnish power for operating farm 
machinery. In the broadest sense, the term farm machinery 
includes farm motors. Owing to a lack of space it will be 
possible to consider only such motors as are in general use for 
agricultural purposes. 

Energy. Energy may be defined as the power of pro- 
ducing a change of any kind. It is the function of a motor to 
utilize and transform energy in such a way that it may be 
used in operating machinery. There are two general forms 
of energy: (1) potential or stored energy, like that con- 
tained in unburned coal; and (2) kinetic, or energy of 
motion, an example of which is the energy of the wind. 

Sources of Energy. The sources of energy which are 
made use of by farm motors are feed, fuel, and the wind. 
The first two of these represent potential energy and the 
last kinetic. 

The Most Important Farm Motors. The motors which 
are used generally for operating farm machinery are the horse, 
the windmill, the gas, gasoline, or oil engine, and the steam 
engine. Other types of motors, such as the water wheel and 
the electric motor, are used to a limited extent for agricultural 
purposes. All of these motors, with the exception of the 
electric motor, are prime movers; that is, they take the energy 




314 AGRICULTURAL ENGINEERING 

in the form of food, fuel, or wind and convert it into mechan- 
ical energy, which may be used in driving machinery. The 
electric motor is driven by electric energy, furnished either 
by an electric generator, driven by a prime mover, or by 
chemical action, like the electricity from an electric battery. 
Forces. A force is that which produces, or tends to pro- 
duce or destroy, motion. A force has two 
characteristics, magnitude or size, and direc- 
tion. The unit by which the magnitude 
of a force is designated or measured is the 
pound. The pound is the action of the force 
of gravity on a definite mass. When two or 
more forces act at a point their combined 
action is equal to the action of one force, 
called the resultant. In a reverse manner a 
force may be divided into components, which act in different 
directions from that of the force. 

Work. When a force acts through a certain distance, or 
when motion is produced by the action of a force, work is 
done. Work is often defined as the product of force times 
distance. 

The Unit of Work. The unit of work is the foot pound, 
or the equivalent of the force of one pound acting through a 
distance of one foot. Thus, for example, the work done in 
raising a weight of one pound five feet or five pounds one foot 
would be five foot pounds. 

Power. Power is the rate of work. In determining the 
rate of work time is a factor. Thus the measurement of 
power consists in determining the number of foot pounds of 
work done in a certain time. 

The Unit of Power. The unit of power in common use is 
the horsepower. It was established arbitrarily, and is 
equal to 33,000 foot pounds of work per minute. Thus if the 



FARM MOTORS 315 

product of the force in pounds by the distance in feet traveled 
in one minute be 33,000, one horsepower of work would be 
done. In measuring horsepower it is customary to determine 
the number of foot pounds of work done in a minute and 
divide by 33,000. For example, suppose a horse walks 165 
feet per minute and exerts a pull of 200 pounds on his traces; 
then the horsepower developed will be: 

200X165 

= 1 horsepower 

33,000 

QUESTIONS 

1. What is energy? 

2. What is the function of a motor? 

3. Explain the two general forms of energy. 

4. What are the principal sources of energy? 

5. Name the most important farm motors. 

6. What is a prime mover? 

7. What is a force? 

8. How may a force be illustrated? 

9. Illustrate resultant and component forces. 

10. Define work. 

11. In what units is work measured? 

12. Define power. 

13. What is the common unit of power and what is its equivalent? 



CHAPTER XLIX 
MEASUREMENT OF POWER 

The Necessity of Measuring Power. The cost of power 
is one of the largest items in the cost of performing farm 
operations. In general, operating costs on modern farms can 
be readily divided into the cost of labor, of power, and of 
machinery. It is desirable to keep each of these items as low 
as possible, as long as it will make the total cost lower. Of 
these three items the labor and power costs are by far the 
largest, and it is desirable that every farmer be able to ana- 
lyze them carefully. In order to determine the cost of power 
accurately, it is necessary to know how the power furnished 
by different motors may be measured and compared. 

Quantities Which Must Be Determined. Power has 
already been defined as the rate of work. Then in measuring 
power it is necessary to determine the amount of work done 
in a certain length of time. Thus the problem is simply a 
matter of determining these three quantities, the force, the 
distance, and the time. 

Measuring the Power of an Engine. The power of an 
engine is commonly measured by applying a so-called Prony 
brake to the pulley or fly wheel. This brake increases the 
friction until the entire power of the engine is required to 
rotate the fly wheel or pulley within the brake when held 
stationary. By allowing the arm of this brake to rest upon a 
scale, the force required to move the pulley or wheel within 
the brake is found. 

The distance traveled in one minute by this force as 
measured by the scale is equal to the circumference of a circle 



FARM MOTORS 



317 



whose diameter is twice the length of the brake arm, times 
the number of revolutions made by the engine in a minute. 
Thus it is seen that it is not difficult to make a simple test of 



'Broke 




Fig. 197. The Prony brake as applied to the pulley of an engine to 
measure the power (From Farm Machinery and Farm Motors). 

an engine. All that is needed is a- brake, a scale for measur- 
ing the force, a speed indicator or revolution counter, and a 
watch to determine the revolutions per minute. 

The distance per minute multiplied by the force as indi- 
cated by the scale gives the number of foot pounds of work 
done in one minute, and this divided by 33,000 gives the 
horsepower. Stated in the form of a formula it is as follows : 



H.P. 



net load on scale X2 X length of brake arm 
(in ft.) X 3.1416 X rev. per min. 

33,000 



Dynamometers. A dynamometer is an instrument used 
in measuring power. The Prony 
brake referred to above may be 
called an absorption dynamome- 
ter, in that in the measurement 
the power is used up by friction. 
A dynamometer which measures Fig traction dVnalrTome'tl^ 1116 




318 



A GRICULTURAL ENGINEERING 



the power while still allowing it to be used in driving the 
machine is called a transmission dynamometer. Instru- 
ments used for measuring the draft of implements in the 
field are called traction dynamometers. Those which simply 
indicate by a needle and dial the draft or force required 




Fig-. 199. A recording' dynamometer as designed by the Agri- 
cultural Engineering- Section of the Iowa Agr. Exp. Station. 



to move the implement are called indicating or direct-reading 
dynamometers. One provided with rolls of paper operated 
by clock mechanism or by a wheel in contact with the ground, 
over which a pencil moves and records the draft, is said to be a 
recording dynamometer. There are also a few kinds on the 
market which average the draft over a measured run. 



QUESTIONS 

1. Why is an understanding of the measurement of power im- 
portant? 



FARM MOTORS 319 

2. What quantities must be determined in the measurement of 
power? 

3. Describe in detail how the power of an engine is measured. 

4. Explain the formula for calculating horsepower. 

5. What is a dynamometer? 

6. Describe an indicating dynamometer. 

7. How is a dynamometer made a recording instrument? 



CHAPTER L 
TRANSMISSION OF POWER 

Not all machines can be so placed as to be driven directly 
by the motor, and so there must be some means of transmit- 
ting the power to the machine. 

Belting. One of the most common forms of transmitting 
power from one rotating shaft to another is by belting. In 
this case the power is transmitted by the friction between the 
belt and the pulley, producing rotation. While transmit- 
ting power a belt is under greater tension on one side, the 
"tight side," than on the other, or "slack side." The actual 
force transmitted is equal to the difference in the tension of 
the "tight side" and the "slack side." The power trans- 
mitted depends also upon the speed of the belt or the distance 
the force travels in a given time. 

Horsepower of Belting. In installing a power plant of 
any sort in which belting is used, it is necessary to determine 
the size of belts which will transmit the desired amount of 
power. A formula quite generally used in estimating the 
horsepower of leather belts is as follows : 

V X w 
H. P. = 

1000 
where H. P. equals the horsepower; V the velocity of the belt 
in feet per minute; and W the width of the belt in inches. 

If the speed of the driving pulley, which furnishes power, 
and its diameter be known, V may be easily obtained by 
multiplying the circumference of the pulley in feet by the 
revolutions per minute. A belt should seldom travel more 



FARM MOTORS 



321 



than 4000 feet per minute, and 2000 feet is a more common 
velocity. 

Leather Belting. Leather is the standard material for 
belting and is considered the most durable, when protected 
from heat and moisture. A good leather belt should last 
from ten to fifteen years when used continuously. It is 
customary to run the belt with the grain or smooth side next 
to the pulley, as the strength of the leather is largely centered 
in this side of the belt; if run with the smooth side out it is 
quite apt to become cracked. 

In order that leather belts should render good service they 
should be properly cared for. 
As a belt bends, the fibers of 
the leather slip over one an- 
other, and for this reason belts 
should be oiled or lubricated. 
Neatsfoot oil is the standard 
oil for this purpose. There are 
many good belt dressings on 
the market, but there are oth- 
ers which are decidedly inju- 
rious. A leather belt works best 

when pliable enough to adhere closely to the pulley, and 
rosin and other such materials are to be avoided. 

Rubber Belting. Rubber belting is made of canvas 
thoroughly covered with rubber. It is made in thicknesses 
of two-ply and up, three- and four-ply being common thick- 
nesses. A rubber belt operates quite satisfactorily under 
wet conditions. 

Canvas Belting. Canvas belting consists of several thick- 
nesses of canvas, four- and five-ply belts being the most com- 
mon. The canvas is thoroughly stitched together and then 
filled with oil to keep out the moisture, and finally painted. 




:?00. Sample of canvas, rub- 
ber, and leather belting- 



322 



AGRICULTURAL ENGINEERING 




The canvas belt is the most economical in cost and is very 
strong. It lengthens and contracts, however, with moisture 
changes; hence is not suitable for pulleys at fixed distances. 
Canvas belting is used largely in connection with agricultural 
machinery, being almost universally used in driving threshers 
and similar machines. 

Lacing of Belts. The common practice of splicing belts 
is by means of a rawhide thong, often called a belt lace. 
Holes are punched at about five-eighths 
inch from each end of the belt and oppo- 
site each other. In order to give greater 
strength, two rows of holes are often 
punched, the second row being set back 
further from the end of the belt. The 
accompanying illustration shows a 
i good style of lacing. The lace on the 
side next the pulley should not cross 
diagonally from one hole to another, but should extend 
directly across the splice. 

Where the belt is to pass around an idler and thus be com- 
pelled to bend in both directions, the hinge lace is most satis- 
factory. There are many forms of patent belt splices and wire 
lacing on the market, some of which are quite satisfactory. 
Several forms permit the ends of the belt 
to be separated by removing a rawhide 
pin which is held in place by the lace. 

Pulleys. Pulleys on which belts run 
are made of wood, cast iron, or steel. 
Wooden pulleys are made in halves, 
arranged to be easily clamped to the 
shaft. Cast-iron and steel pulleys are 
sometimes made in the same manner. 

Wooden pulleys are the cheapest and are very conven 



Fig. 201. 

way to lace a belt. 




Fig. 202. A wooden 
pulley. 



FARM MOTORS 



323 




ient to attach, but are not so durable as those made of metal. 
Metal pulleys are sometimes covered with leather in order to 
increase the friction of contact with the belt. Pulleys from 
which belts are not to be shifted should have a crowned 
face. This will cause the belt to keep in the center of the 
pulley, owing to the fact that the belt 
always tends to run to the highest part 
of the pulley. The pulley which supplies 
the power is generally spoken of as the 
driver, and the one receiving the power is 
designated as the driven pulley. 

Calculating the Speed. It is an easy 
matter to calculate the speed or the diam- 
eter of the pulley, when it is remembered that the diameter 
of a given pulley multiplied by its revolutions per minute is 
equal to the diameter of the driven pulley multiplied by the 
number of its revolutions per minute. If any three of the 
four quantities involved are known, the fourth may be 
easily obtained. 

A common method of transmitting power 
in agricultural machinery is by means of 
link belting running on sprockets. Link 
belting is positive in its action, as there 
can not be any slippage. It is very strong, 
but its use is often objectionable on account 
of the noise which it makes and because 
it cannot be operated at high speed. 
There are several styles in use; in some 
the links or sections are made of malleable iron, and in 
others of pressed steel. Again, some expensive chains are 
made of steel rollers with short steel links riveted on the side. 
Rope Transmission. Where power is to be transmitted 
some distance and where the shafts are not parallel 



Link Belting. 




Fig. 204. A split 
iron pulley. 



324 



AGRICULTURAL ENGINEERING 



ropes running over grooved pulleys or sheaves may be used 
to good advantage. Cotton or Manilla ropes are used 

for this purpose. These 
grooves are arranged so 
as to cause the rope to 
wedge in, thus increasing 
the effect of friction. 

Wire Rope or Cable 
Transmission. Where 
power is to be transmitted 
some distance, as from 
one building to another, 
wire cables can be used to 
good advantage. The pul- 
ley grooves should not 
wedge the wire rope, but 

instead should have a rub- 
Fig. 205. An example of the trans- , „,, , . , , 
mission of power by ropes and shafting. Der Uller On WnLCU tne 

AAA are hangers. i 

rope bears. 
Triangles or Quadrants. The power from a windmill may 

be transmitted to a distant pump t A <-* 



by the use of triangles or quad- L /~'^ 1 

rants, as shown in Fig. 206. If I^JL — 

the wires are long they are sus- 
pended on rocker arms. 

Gearing. A very common 
method of transmitting power in 
agricultural machinery is by means 

° . Fig- 206- Triangles or quad- 

Of gearing. The Construction Of rants used in transmitting 

the teeth is a matter of careful 

design, since they must be made to run smoothly together. 
In cast gears the teeth are cast to shape, while in cut gears 
they are machine made. Cut gears are generally more per- 





FARM MO TORS 



325 




Fig. 207. Spur gear- 
ing. The pinion or 
small gear to the 
r v ght is "shrouded." 



feet, but are more expensive. Gears with parallel shafts 
are called spur gears; those with shafts at ^#53 

an angle are bevel gears. 

Gears transmit power positively, as 
there is no slippage. A small gear wheel 
in mesh with a large one is often spoken of 
as a pinion. 

Friction Gearing. Friction gearing 
transmits power by the friction of two surfaces in contact. 
The face of the driven pulley is usually of cast iron, and that 
of the driver is of paper or rawhide. Fric- 
tion gearing is often used where the slip- 
page is desirable to prevent breakage or to 
start heavy loads. 

Shafting. Power may be transmitted 
from one point to another by means of 
a round shaft, to which pulleys, sprock- 
ets, or sheaves may be attached. This 
shafting is usually supported 
by hangers carrying bearings. 
Collars or rings are attached to the shaft to 
keep it in place. The supporting hangers 
should be near the pulleys, or at such short 
intervals as to prevent excessive vibration of 
the shafting while running. Usually the hang- 
ers are placed from six to eight feet apart. 
The power which the shafting will transmit 
depends upon the material and the revolutions 
per minute, and varies directly with the third 
power of its diameter. 

A common formula for the horsepower of the shafting is: 




Fig. 208. Bevel 
gearing. 




Fig. 209. Worm 
gearing. 



~D a R 



H. P. = 



50 



326 



AGRICULTURAL ENGINEERING 




Fig. 210. Friction 
gearing. 



where H. P. is the horsepower transmitted, D is the diameter of the 
shafting, and E, is the number of revolutions per minute. 

The above formula is for cold rolled steel shafting, the 
kind in general use. 

QUESTIONS 

1. Why is a study of the transmission of power 
an important feature of the study of machinery? 

2. How is power transmitted by a belt? 

3. What is meant by "tight" and "slack" 
sides of the belt? 

4. Give the formula for estimating the horse- 
power capacity of a leather belt. 

5. For what conditions of service is leather 
belting adapted? 

6. Describe the care of leather belts. 

7. For what kind of service is rubber belting best? Canvas? 

8. Explain how a belt should be laced. 

9. Describe the various kinds of pulleys in general use. 

10. Why are some pulleys crowned? 

11. Explain how the rotative speed of one pulley may be obtained 
from another. i£7VXJ 

12. Where may link belting be used to good K*3** 
advantage? 

13. What kinds of ropes are used in rope 
transmission? 

14. Under what conditions should a wire Fig. 211. a link belt 
rope or cable be used? or chain tran smissions. 

15. How may triangles be used to transmit windmill power? 

16. What is the difference between cut and cast gears? 

17. Describe the construction and action of spur gearing. 

18. Give the formula for the horsepower capacity of shafting. 




CHAPTER LI 
THE HORSE AS A MOTOR 

Power from Horses. The horse is the principal source of 
power for agricultural purposes, and will continue to be for an 
indefinite length of time. Considered in the aggregate, the 
horse and the mule furnish a large part of the total power 
utilized for all purposes. In the United States there are 
at the present time approximately twenty-one million head of 
horses and mules. The number has been increasing for the 
past sixty years at the rate of one-third million annually. If 
all of these were at work at one time, power to the amount of 
twelve to fifteen million horsepower would be developed. 

Development. The prehistoric horse was not a large 
animal; but nature and man, by careful mating and selection, 
have produced different types, each suited for a special pur- 
pose, until the modern horse bears but little resemblance to 
the original. As early as 1740 b. c. the horse was used in 
war for transportation. It was not until about the year 
1000 a. d. that history records the use of the horse in the field. 

The development of the horse has necessarily been very 
slow. Greater hardiness, increased size and strength, 
greater beauty, and other desirable characteristics were rec- 
ognized by men who made careful selections for mating and 
awaited results. 

The horse has been called man's best friend in the brute 
world, and the ownership of a good horse is something that 
any man can be proud of. Notwithstanding the fact that 
the horse is an animated thing, it is the chief source of power 
on the farm, and may properly be considered a motor. It 



328 



AGRICULTURAL ENGINEERING 



differs from all mechanical motors in that it is self-feeding, 
self-controlling, self-maintaining, and self -reproducing. 

Classification. The horse in one sense is a heat motor, 
burning fuel in the shape of feed, and as such is a prime mover. 
The thermal efficiency of a horse exceeds that of an average 
steam engine, but does not equal that of a gas or internal- 
combustion engine. 

Capacity of the Horse. The amount of power that a horse 
can develop depends largely upon its size and muscular devel- 
opment. Experiments indicate that a horse exerts a pull on 




Fig. 212. Testing the draft of a horse. Also studying the effect of 
the height and length of the hitch. 

his traces equal to from 1-10 to 1-8 of his weight when the 
working day is not allowed to extend over eight to ten hours. 
The speed at which the horse is able to produce the largest 
day's work is from 2 to 23^ miles per hour. Thus a 1500- 
pound horse walking 23^ miles per hour and exerting a pull 
of 150 pounds, will develop one horsepower; and, furthermore, 
he will be able to continue this for a period not longer than 10 
hours. An increase in the rate of travel, or an increase of 
the effort or draft, must result in a corresponding decrease in 
the length of the working day. 



FARM MOTORS 329 

Maximum Capacity of the Horse. The maximum effort 
of the horse for a short time may exceed his own weight. In 
an actual test a horse weighing 1550 pounds and pulling on 
traces at an angle of 27 degrees with the horizontal exerted a 
pull of 1750 pounds. A draft horse may exert an effort of 
about one-half his weight while walking at a speed enabling 
him to develop, for a short time, as much as four or five horse- 
power. Such trials must be of short duration and be followed 
by periods of rest. 

The fact that the horse is such a flexible motor, being able 
to develop power much in excess of the normal rate, is cer- 
tainly a great advantage for traction purposes, where the load 
is constantly changing because of the condition of the surface 
and the varying grade. Yet this fact often accounts for a 
serious overloading, resulting in an injury to the horse. 

Amount of Service. The horse on the farm does not do 
continuous labor. Investigation in Minnesota indicates that 
the average farm horse does not labor for more than 1000 
hours per year. The useful life of a horse is usually con- 
sidered ten years. 

The Size of Teams. A well-trained horse will direct his 
effort at the command of his master; yet the manageable 
team for field work cannot well exceed four horses. A capable 
driver can drive a four-horse team practically as well as a two- 
horse team and manage almost any of the implements requir- 
ing four horses. It is true that larger teams than four horses 
are in use, but the difficulty connected not only with the 
driving but with the harnessing and hitching will likely pre- 
vent any general increase of the size of the field team beyond 
four horses. As many as 32 horses have been driven by one 
man, but the assistance of several others is required in har- 
nessing and hitching. In driving these large teams, which 
are used principally on the combined threshers of the large 



330 AGRICULTURAL ENGINEERING 

farms of the West, the whole team is controlled largely by the 
two leaders. Thus, if a 24-horse team is to be made up, the 
two leaders will be followed by four horses abreast and these 
by the others arranged six abreast. 

The Principles of Draft. Although horses have been 
used as draft animals since the dawn of history, it is strange 
to note that the principles of draft are not clearly understood, 
many points being open to argument. The individual 
horse owner has not felt justified in making exhaustive experi- 
ments for his own benefit, and no professional experimentalist 
has found it possible to give the matter attention. Mr. T. 
H. Brigg, of England, who studied the subject of horse haul- 
age, states that on an average the horse is made to waste as 
much as 50 per cent of his energies. In farm practice this 
would evidently not be true; yet, if it is only partly true, the 
horse offers a fertile field for profitable investigation. 

The amount of resistance that a horse can overcome, or 
the draft that he can exert, depends upon several factors; viz., 
his weight, height, and length, his grip upon the road surface, 
his muscular development, and the direction of the traces. 

Weight. A heavy horse has several important advan- 
tages over a light one. In the first place his adhesion to 
the road surface is better, — there is less tendency for him to 
slip; and, in the second place, with the heavy horse there is 
less tendency in pulling to lift the forefeet from the ground. 

Height and Length. The latter point also indicates the 
advantage that a long-bodied horse has in pulling. The 
height of the horse may or may not be to his advantage, 
depending upon the height of hitch. It is common occur- 
rence to see the efforts of a horse limited by his weight and 
length, as his forefeet are lifted from the ground without 
permitting him to exert his full strength. It is an easy matter 
to demonstrate that a horse can increase his maximum 



FARM MOTORS 331 

effort about 200 pounds by having a man sit astride his 
shoulders. Experienced teamsters with light teams often 
make use of this method of assistance in an emergency pull. 

Grip. The grip of the horse refers to the hold that he 
secures on the surface of the road or ground. Thus, for 
example, it is obvious that a horse without sharp shoes could 
pull but little on ice. In like manner the horse is often 
unable to obtain a sufficient hold on hard ground or pavement 
to exert his full strength. 

Muscular Development. It is necessary that the horse 
have large and powerful muscles, for these are really the 
motors that do the work. The object of the breeder of draft 
horses has always been directed toward the development of 
the muscles as well as the increase in size. 

The Proper Angle of the Traces. The proper direction 
or angle of trace is a question on which there is much differ- 
ence of opinion. In fact there are two phases of the subject; 
first, the angle of trace with which the horse will labor with 
the most comfort and ease; and second, the angle of trace 
which will move any load with the least force. The first of 
these is the most difficult to study. If the horse can realize 
that certain positions of the hitch, the trace, and the collar are 
most comfortable, he cannot tell his master so. The angle of 
trace has a very decided effect upon the maximum effort of a 
horse. A low trace has a tendency to pull the horse into the 
surface, thus adding to his adhesion and grip and overcoming 
to a considerable extent the tendency to lift the forefeet from 
the ground. It is undesirable to maintain a low trace con- 
tinually, because the horse is compelled to carry more or less 
of the load when less effort would be required to draw it. 
For maximum speed it may be desirable to carry a part of 
the horse's weight on the truck, and the racing sulky, whether 
purposely or not, is arranged to do so. 



332 AGRICULTURAL ENGINEERING 

Referring to the angle of trace for the minimum draft, i t 
is to be recognized that there are two distinct classes of imple- 
ments to which horse labor is applied : (1) those intended 
primarily for moving heavy weights from place to place; 

and (2) those designed to work 
the soil. In the first case the draft 
is due chiefly to the friction of 
the machine and the rolling or 
sliding resistance of the surface. 
Thus, in Fig. 213, it is to be noted 
^ Pleost , that a certain force, W, will lift 



JL. 



/ "" D ' _// the block, A, and another force, 
F, will slide it on the surface. 



Fig\ 213. A sketch illustrating mi 1 , r i ,i , -n 

the angle of least draft. The least force, however, that will 
produce motion lies between 
these two, as D, and its direction depends upon the magni- 
tude of each of the other two forces. In mechanics the 
angle this force makes with the horizontal is called the angle 
of repose. If the load is to be drawn up an incline, the 
proper angle of trace should equal the ordinary angle plus 
the angle of the grade. With an implement like the plow, the 
line of least draft extends almost directly to the center of the 
place where the work is being performed. 

The Length of Hitch. Lengthening the hitch does not 
have the effect that it is generally supposed to have. The 
principal effects are that the horse does not have as complete 
control over the load and that the angle of trace is changed. 
Lengthening a horizontal trace ten or even fifty feet has 
practically no effect upon the capacity of the horse. Men 
are often found who think they can hold a horse at the end of 
a 50- or 100-foot rope. A trial is very convincing that they 
cannot do so. 



FARM MOTORS 333 

QUESTIONS 

1. Why is the horse the principal source of farm power? 

2. To what extent has the horse been developed as a farm motor? 

3. In what way does the horse differ from mechanical motors? 

4. What kind of motor is the horse? 

5. What relation is there between the weight of a horse and the 
power it can develop? 

6. How does an increase in the speed or length of working day 
affect the power of the horse? 

7. To what extent can a horse deliver power in excess of the nor- 
mal rate? 

8. How many hours of service does an average farm horse render 
in a year? 

9. Explain how horses may be arranged in large teams for heavy 
loads. 

10. Upon what factors does the amount of resistance a horse can 
overcome depend? 

11. How does the height and length of a horse affect the resistance 
he can overcome? 

12. What is meant by a horse's grip? 

13. Explain the importance of muscular development in a draft 
horse. 

14. Discuss the influence of angle of trace on draft. 

15. Why is the angle of least draft not always best? 

16. How does the length of hitch affect the resistance a horse can 
overcome? 



CHAPTER LII 
EVENERS 

The use of four- or five-horse teams, as now required for 
many implements, introduces many perplexing problems in 
connection with the hitch and the eveners for dividing the 
work evenly among the animals. In addition to the increase 
in the size of teams used with gang plows, disk harrows, drills, 
harvesters, etc., the tongue truck and the complicated patent 
evener have been introduced, which add to the difficulty of 
understanding the mechanics involved. 

There is little difficulty in dividing the load equally 
between the members of a two-horse team. The doubletree 
may be of any reasonable length, depending on whether it 
is desired to work the horses close together or to spread them. 
To divide the work equally between two horses, the end 
holes for attaching the singletrees should be equally distant 
from the center hole. The wagon doubletree is usually 44 
inches long, and the plow doubletree 30 inches. Large horses 
cannot be worked as closely as smaller ones. It is undesir- 
able to work horses too closely, as all are worried more or less 
by not having sufficient room. 

The Placement of Holes. When the horse is pulling on 
the end of an evener, his advantage or leverage is equal to 
the perpendicular distance between the extended line of 
draft and the line of resistance passing through the center 
hole, or the fulcrum, of the evener. This is illustrated in 
Fig. 214. If all the holes in the evener are in line, it makes 
little difference whether or not it is kept at right angles to 
the direction of movement. If the center hole is not in line 



FARM MOTORS 



335 



with the two end holes, then the load is divided evenly only 
when the two horses pull evenly together. If one horse pulls 
in advance of the other, the load is no longer evenly divided. 
It is customary to place the end holes well toward the rear 
edge of the evener, and the center hole well toward the front 
edge. This placement of the holes adds materially to the 
strength of wooden eveners. 

When the holes are much out of line and when the horses 
do not pull evenly, there may be much difference in the efforts 
of each. In Fig. 214, which shows a wagon doubletree in 




Fig. 214. 



A wagon doubletree illustrating the effect of not havini 
holes for the clevis pins in a straight line. 



actual use, the rear horse would be compelled to pull 8.4 per 
cent more than the leading horse, the end of whose double- 
tree is only eight inches in advance. 

Three-Horse Eveners. In order to divide a load among 
three horses, it is necessary to introduce a second lever, or 
some other device to take its place. A usual method of 
arranging such an evener is shown in Fig. 217. This is a 
combination evener, which in this instance does not space the 
horses evenly but indicates the general arrangement of the 
three-horse evener, or tripletree. The factory-made triple- 



336 



AGRICULTURAL ENGINEERING 



tree usually has short metal levers placed over a wooden 
evener, as illustrated in Fig. 215. This gives the advantage 
of a shorter hitch. A shorter hitch will not cause an appre- 




215. A factory-made tripletree which offers advantage of a close 
hitch. 

ciable reduction of the draft, but will enable the team to 
have better control over the implement. 

Four-, Five-, and Six-Horse Eveners. The four-horse 
evener is usually made as illustrated in Fig. 217. This con- 
sists in a four-horse evener with two doubletrees attached. 

The plain five-horse evener is made as shown in Fig. 216. 
The dimensions given are right for medium-sized horses when 
it is desired to work them together as closely as practical. 

There has been a decided increase in the use of the 14-inch 
gang plow during recent years. This plow makes a load too 
heavy for four average horses, and five or six horses should 
be used. It is undesirable to work five horses abreast, for, 
if one horse walks in the furrow and the other four on the land, 
the load or line of draft does not come directly behind the 
center of the team and there will be much undesirable side 
draft. It is better to put two horses in the lead and use 




Fig. 216. A plain five-horse evener. 



eveners such as those shown in Fig. 217. This will put the 
team directly in front of the load and will avoid the side draft. 
Instead of the short levers placed under the rear doubletree 



FARM MOTORS 



337 



to equalize the draft between the leaders and the two horses 
directly behind them, a short, vertical evener of metal or a 
chain and pulley may be used. In the case of the five-horse 
evener, the end hole for the single horse hitch should be 
four times as far from the center hole of the evener as the end 
hole for the four horses working in pairs. In case of the six- 
horse evener, the hitch for the team should be twice as far 
from the center hole as the 
hole for the four-horse 
hitch. 

Plain Eveners. Simple 
or plain eveners are much 
to be desired. There is 
absolutely nothing to be 
gained by a complicated 
system of levers and tog- 
gle joints. If there is to 
be an equalization of the 
draft, there should be a 
flexible hitch; and if the 
evener is attached to the 
plow or other implement 
at more than one point, the hitch cannot be truly flexible. 

Overcoming Side Draft. With four horses hitched 
abreast, on a sulky plow the line of draft lies outside of the 
line of resistance, and there is a tendency to throw the front 
end of the plow away from the land. This tendency can be 
partly overcome by adjusting the front furrow wheel in such 
a manner as to pull the plow toward the plowed land, as pre- 
viously discussed. (See page 203.) 

The tongue truck is the only satisfactory means of off- 
setting draft, and for this purpose it is a commendable device. 
The truck should be provided with heavy flanged wheels 




i. combination three-, four- 
and six-horse evener. 



338 



AGRICULTURAL ENGINEERING 



which will engage the surface of the ground and give a thrust 
directly across the line of draft. This arrangement, no 
doubt, adds a little to the draft, but it adds much to the con- 
venience of handling the team, especially on the harvester. 
When three horses are to be hitched to an implement with 
a tongue attached in the line of draft, much may be accom- 
plished by crowding the two horses on one side of the tongue 

as closely together as pos- 
sible and putting the sin- 
gle horse out as far as 
possible. 

Fig. 218 shows an at- 
tempt offered in an agri- 
cultural paper some time 
ago as a successful method 
of overcoming side draft 
Fig. 21s. a futile attempt to remove on a disk harrow with two 

side draft when the team is not placed , . , £ , 

directly in front of the load. An offset horses On One Side 01 the 
tongue should be used. , , . , 

tongue and one on the 
other. The chain pulls back precisely the same amount that 
it pulls the one side of the disk harrow ahead. 




C/iem 



QUESTIONS 

1. Why is it more important to study eveners now than formerly? 

2. How closely should horses work? 

3. Explain how the placement of the clevis holes of a doubletree 
may influence the distribution of the load. 

4. Describe the construction of three-horse eveners. 

5. Explain how an evener may be arranged to hitch five or six 
horses to a plow. 

6. Why are simple or plain eveners desirable? 

7. What is the best way to overcome side draft? 

8. Why is it not possible to remove side draft by running a chain 
across a machine? 



CHAPTER LIII 
WINDMILLS 

Utility. The windmill is adapted to work which may per- 
mit of a discontinuance during a period of calm. It is 
adapted to regions where wind of a velocity sufficient for its 
operation prevails generally throughout the year. One line 
of work which will permit of a discontinuance during calm is 
pumping, and for this reason the use of the windmill is con- 
fined largely to this work. 

When properly installed and working under proper condi- 
tions, the windmill is perhaps one of the most economical of 
all motors. As a source of energy it costs nothing; the cost 
of the power is due solely to the interest on the investment 
and to depreciation and repairs. 

Development. The use of windmills dates back to a 
very early time. Wind and water wheels were used as the 
first source of power long before heat engines were thought 
of. The windmill years ago reached a rather high stage of 
development in Europe, those of Holland being especially 
famous. The Holland or Dutch mills represent a distinct 
type, in that there were usually four canvas sails mounted on 
a wooden frame. The speed was regulated by varying the 
amount of sail surface exposed to the wind. In most cases 
the mill was turned toward the wind by hand. The steel 
windmill was developed in the United Stated about 1883. 

The Wind. Wind is simply air in motion. It represents 
kinetic energy, and the windmill obtains power from it by 
reducing its velocity, causing a certain amount of energy to 



340 AGRICULTURAL ENGINEERING 

be given up. It is easy to see that it would be impossible to 
reduce the velocity to zero and obtain all of the energy of the 
wind, because it must flow past the windmill. 

Types of Mills. There are many types of windmills on 
the market, and they may be classified in several ways: (1) 
by the material used in construction, (2) by the type of con- 
struction, and (3) by the use to which they are put. For- 
merly the wheels were made almost entirely of wood, but 
steel has now practically displaced wood. It is claimed by 
good authorities that the steel wheel is more efficient and 
will operate in a lighter wind than the wooden wheel, owing 
to the thinness and the shape of the fans. Windmills may 
be also either direct-stroke mills or geared mills. Direct- 
stroke mills are used solely for pumping purposes; a stroke is 
made with each revolution of the wind wheel. In order to 
produce a mill which will operate in lighter winds, gearing is 
often used to reduce the number of strokes in proportion to 
the number of revolutions of the wheel. Most steel mills are 
now geared in this way. 

Windmills used solely for pumping are called pumping 
mills, and the power is transmitted from the wind wheel by 
means of a pumping rod having a reciprocating motion. 
When a rotating motion is desired a vertical shaft is run from 
the mill to a point from which the power may be transmitted 
to a machine by any of the more usual methods. Such a mill 
delivering its power by a rotating shaft is said to be a power 
mill. 

Size of Mills. The size of windmills is indicated by the 
diameter of the wheel. Common sizes used for pumping 
purposes are 8- and 10-foot wheels. Power mills are often 
built much larger, with wheels 20 or more feet in diameter. 
Wheels of large diameter must be made very strong to be 
able to withstand the wind, and the extra weight thus 



FARM MOTORS 341 

required tends to reduce the efficiency. Especially large 
windmills have been attempted, but they have not been 
successful. 

Construction. The most important points involved in the 
construction of a windmill are the strength and the rigidity 
of the wind wheel and the durability of the bearings and gears. 
The wheel must necessarily be light, yet it must be carefully 
constructed or it will not be able to withstand the strenuous 
service imposed upon it. The bearings should be large, of 
material that resists wear, and be easily replaceable. The 
gearing should also be of liberal dimensions. 

Lubrication. One of the most important features of the 
windmill is provision for adequate lubrication by means of 
magazine oilers or lubricators, one filling of which will supply 
sufficient lubrication to last for a month or more. Many 
mills are destroyed by failure to give them attention in this 
respect. Some makers have tried to provide roller bearings 
which will not be seriously damaged when adequate lubrica- 
tion is not provided. 

Regulation. All windmills must have some means of reg- 
ulating the speed. One common method is to have a small 
side vane that turns the wind wheel edgewise to the wind as 
the velocity of the wind becomes high. Another plan is to set 
the wheel to one side of the center of the mast on which it is 
mounted, when the unequal pressure tends to turn the wheel 
away from the wind. Again, windmills have a tendency to 
turn around on the mast as the rotating speed increases, and 
this tendency is made use of in regulating speed. In some 
wheels the sections are hinged and are connected with a 
centrifugal governor which allows them to be turned par- 
tially out of gear as the wind velocity increases. 

Power of Windmills. One authority concludes that the 
power of a windmill increases as the cube of the wind velocity 



342 



AGRICULTURAL ENGINEERING 



and also as the square of the diameter of the wheel. A later 
investigator found that the power varied more nearly as the 
square of the wind velocity and about the 1.25th power of 
the diameter of the wheel. The following table, reproduced 
from the work of Mr. E. C. Murphy, indicates in a general 
way the amount of power furnished by different kinds of mills 
under different conditions. 

Power furnished by windmills under different conditions. 











Velocity of 








Diameter 


Number of 


wind in 


Horse- 


Name 


Kind 


in feet 


sails 


miles per 
hour 


power 


Monitor 


wood 
wood 


12 
14 


96 
102 


20 
• 20 


.357 


Challenge 


.420 


Halliday 


wood 


22.5 


100-144 


20 


.89 


Aermetor 


steel 


12 


18 


20 


1.05 


Ideal 


steel 


12 


21 


20 


.606 


Perkins 


steel 


14 


32 


20 


.609 



Towers. Like the windmill proper, the tower may be 
built either of wood or steel. With the increase in the cost 
of wood the steel tower has come into more general use. The 
usual height of tower for a pumping mill varies from 20 to 
60 feet. The wooden tower usually has four posts made of 
4x4 or 5x5 material. The steel tower is made up of three or 
four posts of angle irons. The steel tower is now almost 
universally galvanized for protection against corrosion. This 
is also true of the steel windmill. It is desirable to have the 
wheel placed well above all obstructions to the wind, in the 
way of trees, buildings, or embankments. A small wheel 
on a high tower is regarded as better than a large wheel on a 
lower tower which does not permit the wind to reach the 
wheel with full force. 



it? 



FARM MOTORS 343 

QUESTIONS 

1. To what kind of service is the windmill adapted? 

2. Is the windmill an economical motor? 

3. How long has the windmill been used? 

4. How does the windmill obtain power from the wind? 

5. Can the windmill obtain all the energy of the wind which strikes 



6. How may windmills be classified? 

7. What is the difference between a direct-stroke and a back- 
geared mill? 

8. To what uses may a power mill be put? 

9. How is the size of a windmill designated? 

10. What are some of the important features of the construction 
of a windmill? 

11. What special provision for lubrication may be provided? 

12. Describe how the speed of a windmill may be regulated. 

13. How does the power of a windmill vary with the diameter of 
wheel? 

14. How does the power of a windmill vary with the wind velocity? 

15. Describe the construction of the windmill tower. 



CHAPTER LIV 

THE PRINCIPLES OF THE GASOLINE OR OIL 

ENGINE 

Relative Importance. The general introduction of the 
gasoline or oil engine to do certain classes of work on the farm 
places it next to the horse in importance among the various 
farm motors now in use. So general has become its intro- 
duction and so varied its uses that it is now imperative that 
every farmer be familiar with the principles of its operation 
and the essentials of its successful management. 

Classification of Motors. The gasoline or oil engine is a 
heat engine, since its function is to convert heat or heat 
energy, liberated by the combustion of gasoline or oil, into 
mechanical energy. With this respect it is to be classed 
with any motor using fuel of any sort. 

The gasoline or oil engine is an internal-combustion engine 
or motor, in which the fuel, along with a sufficient amount of 
air to support combustion, is ignited inside of a closed cylin- 
der. The steam engine might be styled an external-combus- 
tion engine, in that the combustion takes place outside of the 
boiler or vessel withholding the pressure produced. In the 
internal-combustion engine the heat released causes an 
increased pressure of the gases in the cylinder, including the 
products of combustion, which push upon the piston and 
cause it to move forward, allowing the gases to expand and 
do work. 

Fuels. The gasoline or oil engine does not differ essen- 
tially from the gas engine, the difference consisting primarily 
in a device called the carburetor, provided to convert the 



FARM MOTORS 



345 



liquid fuel into a gas. Kerosene and fuel oils are more diffi- 
cult to vaporize, or gasify, than gasoline, and for that reason 
a special carburetor must be provided when they are used; 
but in other respects the kerosene 
or fuel oil engine does not differ es- 
sentially from the gasoline engine. 
For this reason it is entirely cor- 
rect to speak of all internal-com- 
bustion engines burning either gas 
or liquid fuels after this manner as 
gas engines. 

The gas engine is very simple, 
more so, in fact, 
than the steam 
engine. The 
accuracy with 
which the va- 
rious functions 
must be perform- 
ed is the only thing which prevents the 
gas engine from being a simple affair to operate. 

Types. There are two general types of gas engines on the 
market. These are known as the two-cycle and the four- 
cycle engines. It is perhaps more proper to style these types 
as the two-stroke cycle and the four-stroke cycle, inasmuch as 
two and four strokes of the piston are required to complete 
the cycle in each type, respectively. 

A cycle is a term used to designate a complete set of 
operations which must take place in every engine to enable it 
to do work. The appli cation of work or the liberation of energy 
in the gas engine is intermittent. This is true of all recipro- 
cating motors, but more operations are required in the gaso- 
line engine than in the steam engine. The four-stroke cycle 





buretor. 



Fig. 220. A kero- 
sene carburetor in sec- 
tion. One of the noz- 
zles is for water. 



19. A gasoline car- 
The gasoline is 
vaporized by the air as it is 
drawn past the nozzle. 



346 



AGRICULTURAL ENGINEERING 



engine is the more simple to explain of the two types and, for 
that reason, should be considered first. It is to be assumed 
that the reader understands the gas engine to consist of the 
essential parts as illustrated in Fig. 221. These parts, as 
far as a consideration of the cycles is concerned, consist of a 
cylinder with a gas-tight piston attached by a connecting rod 
to a crank on which the fly wheels and pulleys are attached, 
and two valves, an inlet valve to let the gases into the 




221. Illustrating the operations which take place in a four-stroke 
cycle engine to obtain a power or working stroke. 

cylinder and an exhaust valve to let the burnt gases out. 

Four-Stroke Cycle. The four strokes in the four-stroke 
cycle engine are: (SeeFig. 221.) 

First, the suction stroke, during which the piston increases 
the volume of the space at the closed end of the cylinder and 
thus draws into the cylinder through the inlet valve a charge 
of vaporized fuel, and enough air to furnish a sufficient 
amount of oxygen to support combustion. 

Second, the compression stroke, during which the piston 
makes a return stroke and compresses the gases into the clear- 



FARM MOTORS 347 

ance space at the end of the cylinder. This operation is 
necessary in order to get the full power out of the fuel. 

Third, the expansion stroke. Just before the end of the 
compression stroke the ignitor acts so that combustion takes 
place; and at the end of this stroke there is a high pressure 
ready to act under the piston, pushing it forward, thus doing 
the work. 

Fourth, the exhaust stroke, during which the piston 
returns toward the closed end of the cylinder and the exhaust 
gases are pushed out through the exhaust valve. At the end 
of this stroke the piston is again at the beginning of the suc-^ 
tion stroke. To complete the cycle it is noticed that two 
entire revolutions of the crank shaft and fly wheels have been 
required and that only one of these four strokes is a working 
stroke, or a stroke during which the engine is receiving power. 
During the other three strokes the fly wheels must furnish the 
energy to keep the engine in motion. 

Two-Stroke Cycle Engine. The two-stroke cycle engine 
is an attempt to increase the number of working strokes by 
providing an auxiliary chamber in which the gasoline or fuel 
mixture is given such an initial compression that at the end 
of the exhaust stroke these fresh, unburned gases under com- 
pression readily displace the burned gases. This displace- 
ment takes place so quickly that it is possible to compress the 
fresh gases during the return stroke. These operations are 
shown in Fig. 222, which shows in outline an engine using the 
crank case as a compression chamber. Owing to the larger 
number of working strokes for a certain rotative speed the 
two-cycle engine has the advantage of light weight. 

As the events in the two-cycle engine occur in every revo- 
lution instead of once in two revolutions, the two-cycle engine 
is of more simple construction. A secondary shaft operated 
by a reducing gear for opening the valves and making one 



348 



AGRICULTURAL ENGINEERING 



revolution to two of the crank shaft, is not required, and in 
many engines the main valves are dispensed with by making 
the piston uncover ports or openings in the cylinder walls for 
the admission of fresh gases and the escape of those burned. 
This simplicity of construction enables the two-cycle engine 




Fig. 222. Illustrating the operations which take place in the two-stroke 
cycle engine. A, suction into crank case. B, compression in crank 
case. C, compression in cylinder combined with A. D, expansion in 
cylinder combined with B. (From Farm Machinery and Farm Motors.) 

to be built and sold at a lower cost than the four-stroke cycle 
engine. 

On the other band, the two-cycle engine does not operate 
with the same economy in fuel consumption as the four-stroke 
cycle. If the cylinder diameter is large, the mixing of the 
fresh and burned gases is so great that there cannot be the 
best scavenging or cleaning of the burned gases from the cylin- 
der without a loss of unburned gases to the exhaust. Very 
large engines are made on the two-cycle plan by introducing 
an auxiliary air-compression cylinder which blows air to clean 
out the burnt gases. 

The two-cycle engine is a little more difficult to manage, 
as a rule, and the carburetor and the ignition system are more 
susceptible to slight misadjustments. This is no doubt 
largely due to the fact that there cannot be as sharp a suction 
upon the carburetor as may be had with the four-cycle engine. 



FARM MOTORS 349 

This sharp suction is very valuable in assisting to vaporize 
the fuel by the rapid rush of air through the carburetor. 

QUESTIONS 

1. Why is the gasoline or oil engine an important farm motor? 

2. To what class of motors does the gasoline or oil engine belong? 

3. Why is the gas or oil engine an internal-combustion engine? 

4. Why is it correct to speak of the gasoline or oil engine as a gas 
engine? 

5. Describe the four-stroke cycle type of engine. 

6. Describe the two-stroke cycle type of engine. 

7. Compare the advantages of the two-stroke and four-stroke 
cycle engines. 



CHAPTER LV 
ENGINE OPERATION 

Essentials of Operation. Someone has said that there 
are four features of the action of the gasoline or oil engine 
which must be right or the engine will not run and furnish 
power; and if they are right, the engine will run in spite of 
everything, assuming for the time being that the working 
parts are in such adjustment as to permit of free move- 
ment. These essential features are: 

1. Proper mixture of gases. 

2. Compression. 

3. Ignition. 

4. Correct valve action. 

The Gas Mixture. During the suction stroke of the 
piston the cylinder is drawn full of air mixed with a suffi- 
cient amount of fuel vapor. The amount of air and fuel 
vapor must be in about the correct proportion or the mixture 
will not burn. For instance, if there be little fuel or if it be 
improperly vaporized, the mixture will not be ignited by the 
spark produced by the igniter. On the other hand, the mix- 
ture will not burn if the proportion of fuel vapor be too large; 
oxygen of the air must be present to support combustion. 
Pure fuel vapor or gas will not burn, nor will very rich mix- 
tures. 

Now the range of proportions in which the air and fuel 
vapor may be mixed and still give a combustible mixture is 
quite limited, and the range of mixtures which will give a 
good, strong working stroke is still more limited. The richest 
mixture that will burn has been stated by one authority to 



FARM MOTORS 



351 



be about one part of gas or fuel vapor to four parts of air. 
The same authority gives one part of fuel vapor to "fourteen 
parts of air as being the leanest mixture that will burn. 

It is to be remembered in this connection that of every 
one hundred parts of air only 23 parts are oxygen; and it is 
the oxygen that supports combustion. The largest constitu- 
ent of air, nitrogen, composes about 77 parts of the one 
hundred. Nitrogen is entirely inert, and 
in the gasoline engine cylinder it occu- 
pies space which would be more desir- 
ably filled with gasoline and oxygen. 

In changing from a liquid to a vapor, 
the fuel is increased in volume some 600 
to 1000 times. This means that the 
ratio of the volume of liquid fuel used to 
that of air must vary from 1 to 8000 up 
to about 1 to 16,000. From this we see 
why the carburetor of the gasoline engine 
is such a sensitive affair. 

Not only must the ratio of fuel to air be quite constant, 
but the difficulties encountered are magnified by the fact that 
the mixing must take place between colorless gases and "sight 
unseen" inside the engine cylinder. The gas engineer must 
resort to tests that will show the condition of the mixture. 

If the mixture can be adjusted until it will burn, then the 
adjustment for the proper mixture is easy. A too rich mix- 
ture is indicated by black smoke from the exhaust; and one 
too lean, by a sharp, prolonged exhaust, indicating a slowly 
burning mixture. The smoke of a too rich mixture is black, 
while that caused by too much lubricating oil is blue. 

When the engine is provided with a hit-or-miss governor, 
the needle or supply valve should be adjusted to require the 
least number of explosions necessary to furnish a given 



Fig. 223. An au- 
tomatic carburetor, 
shown in section, 
which supplies addi- 
tional air through an 
auxiliary air valve 
when the engine 
runs at high speed. 



352 AGRICULTURAL ENGINEERING 

amount of power and then be slightly closed. The adjust- 
ment which gives the least number of explosions does not give 
the most economical setting of the needle valve, and that is 
why the valve should be closed slightly. 

Testing the Mixture. The most perplexing trouble 
comes when it is impossible to get a single explosion. In this 
case certain tests must be made to determine whether the 
cylinder is flooded with fuel or whether there is not enough 
gasoline vapor present to make an explosive mixture. Of 
course, tests should be made to determine that the ignition 
system is perfect and that an explosive mixture would be 
ignited if there should be one in the engine cylinder. 

One plan to follow is to shut off the fuel supply and clear 
the cylinder thoroughly of all gasoline by turning the engine 
over several times. This being done, an entirely new attempt 
to start the engine will usually meet with success. 

A test may be made of the nature of the mixture in the 
cylinder by holding a lighted match to the relief cock as the 
engine is turned over. A rich mixture will burn as it comes 
in contact with the air; an inflammable mixture will snap back 
into the cylinder; and a mixture which is too lean will not 
burn at all. 

The Compression. It is necessary that a gasoline engine 
compress the mixture of gasoline vapor and air before ignition 
or the full power of the fuel will not be obtained. Failure 
to secure compression is usually due to leaks, either past the 
piston or through the valves. 

Leaks. Piston rings are provided to make a gas-tight fit 
between the piston and the cylinder. Sometimes these rings 
become stuck in their grooves by charred oil and do not 
spring out against the cylinder walls as they should. When 
this happens, which usually is due to the use of poor lubricat- 
ing oil, the rings should be thoroughly cleaned. Where the 



FARM MOTORS 



353 



trouble is not serious, the rings may be loosened by feeding in 
kerosene through the lubricator. When the rings become 
worn, they should be replaced. 

Leaks may also take place past the valves. Often 
charred oil will lodge on the valve seat, preventing it from 





Fig. 224. A sectional view of a gas engine cylinder, showing 
the cylinder volume j>nd clearance space. 

closing tightly. Cleaning will often overcome this difficulty ; 
but when scored or pitted, the valve must be ground on its 
seat with emery and oil until a perfect fit is again secured. 



QUESTIONS 

1. What are the four fundamental essentials of gas engine 
operation? 

2. What is meant by an explosive mixtuie? 

3. What are some of the difficulties encountered in obtaining an 
explosive mixture? 

4. What are the indications of a rich mixture? A lean mixture? 

5. Explain how the quality of the mixture may be tested. 

6. How does compression influence the power of an engine? 

7. What are the common causes for the loss of compression? 



CHAPTER LVI 
GASOLINE AND OIL ENGINE OPERATION (Continued) 

Ignition. The burning of the fuel in a steam plant is 
continuous from the time of kindling the fire until the plant is 
shut down. In the gasoline engine the fire is quickly extin- 
guished, lasting but a part of one stroke of the piston, necessi- 
tating the igniting of additional fuel as it is taken into the 
cylinder. It is easy to see that if for any reason there is a 
failure to ignite the fresh fuel, no power will be obtained from 
that particular cylinder. As in the case of failure to secure 
the proper mixture and compression, the gas engine will not 
operate unless each charge is successfully ignited. 

Development. As indicated, the firing of the charge in 
the cylinder is spoken of as the ignition, and the devices that 
accomplish it the ignition system. One of the principal diffi- 
culties encountered by the early inventors in developing the 
gas engine was that of securing ignition. The early attempts 
consisted largely in carrying an open flame into the cylinder 
by means of suitable valves. Later, the hot tube was used 
generally, and is to some extent at the present time. The 
hot-tube igniter consisted of a short length of pipe screwed 
into the compression space and kept at red heat by means of 
an outside flame. During compression the unburned gases 
pushed the burned gases up into the tube until the fresh fuel 
came in contact with the hot surface of the tube, causing 
ignition. It is not possible to regulate the time of the ignition 
with the hot tube as accurately as desired, and when used with 
a small engine, at least, the fuel required to keep the tube hot 
is often an important part of the entire cost of operation. 



FARM MOTORS 



355 



These shortcomings on the part of the hot-tube igniter, and 
the rapid development of the electric igniter have caused the 
general abandonment of the former. 

There are two general classes of electric ignition systems 
in general use. These systems are generally known as the 
"make-and-break" system and the "jump-spark" or high- 
tension system. Each of these systems has its advantages. 
The make-and-break system is used largely in connection 
with stationary engines, while the jump-spark is used with 
variable-speed motors, like the automobile. 

The Make-arid-Break System. In the make-and-break 
system of electric ignition two electrodes or points are pro- 



Itpnilor 
* S Rod 




fc&ttery of Dry Cells 



\^ss\\\\\\\\\\\^^X 



Fig. 225. Sketch showing the wiring and essential parts of a make- 
and-break system of ignition. Four standard dry cells form the usual 
battery instead of six as shown. 

vided in the compression space of the engine cylinder, and are 
insulated from each other in such a way that an electric cur- 
rent will not flow through them unless they are made to 
touch each other. When an electric current is broken, there 
is a tendency to produce a spark at the point where the separa- 
tion takes place. By placing a spark coil in the circuit the size 
of the spark may be much increased. The system consists 



S56 AGRICULTURAL ENGINEERING 

primarily in providing a source of electricity and suitable 
mechanism to bring the points together at the proper time 
and to separate them at the proper time for the sparks so pro- 
duced to fire the mixture in the cylinder. 

The make-and-break system does not use high-tension or 
high-voltage electricity. Voltage corresponds to pressure, 
or ability of the electricity to overcome resistance. For this 
reason the make-and-break system does not require such 
careful insulation as does the high-tension system. There 
are, however, the moving parts inside of the cylinder, and 
the mechanism operating it is such that it is not convenient 
to make provision for varying the time of ignition. Failure 
on the part of the make-and-break system may be generally 
traced to failure in the source of current, or to a break-down 
of insulation. There are many other minor causes of failure, 
but space does not permit a discussion of them here. 

Testing the Make-and-Break System. When an engine 
fails to start, a test should be made of the ignition system. 

— — — , This is generally done by making and break- 

g* !&.--,. ing the circuit by hand outside of the engine 

dR| cylinder, and judgment is then passed upon 

the size of the spark as to whether or not 

it is sufficient to ignite the charge. After 

make- a n d-break the insulation on the wires becomes worn 

and damaged, there may be an escape of 

electricity without passing through the igniter points. The 

igniter points may become covered with scale, oil, or dirt 

which will prevent the electricity from passing from one to 

the other when desired. Often the movable points fail to 

work freely, owing to lack of oil, preventing the sharp, quick 

separation of the points, which is quite necessary to secure a 

good, fat spark. 



FARM MOTORS 



357 




227. Sketch showing the essential 
parts of a jump-spark system of igni- 



The Jump-Spark System. The jump-spark system does 
not have any working parts inside of the cylinder, where they 
are exposed to the high temperature there present. The 
mechanism is such that 
it is convenient to vary 
the time of ignition when 
this is used to regulate the 
speed of an engine, as it is 
in the case of the automo- 
bile engine. The jump- 
spark system requires the 
use of an induction coil, 
which, when connected to 
one of the usual sources of 

electricity, increases, the voltage to such an extent that when 
suddenly cut off the new or induced current jumps a small 
gap. The usual spark plug is only a provision for placing 
this gap inside of the engine cylinder. Owing to the high 
voltage of the jump-spark system, certain wires must be 
very carefully insulated in order that the gap of the spark 
plug shall be the path of least resistance for the current 

to escape. 

Testing. It has been 
suggested that tests be 
made with the make-and- 
break system of ignition 
to determine whether or 

Fig. 22S. A jump-spark or induction coil not the System is in WOrk- 
dissembled to show construction. • i v . t_i 

mg order when trouble is 
encountered. A convenient way of testing the jump-spark 
system is to remove the spark plug and lay it upon the 
cylinder and manipulate the circuit-breaking mechanism by 
hand. If a good spark be obtained, it may be assumed 




358 



AGRICULTURAL ENGINEERING 




Fig. 229. J 
spark plug ii 
section, show 
ing construe 
tion. 



that the trouble lies elsewhere than in the ignition system. 
The Batteries. Any form of electric ignition requires a 
source of electricity. One of the most general forms on the 
market is the dry-cell battery. It represents, 
perhaps, the cheapest source of electricity, as 
far as first cost is concerned. When the cells are 
able to furnish a sufficient quantity of electricity, 
they are very satisfactory. One of the most 
perplexing features of the use of dry-cell bat- 
teries is the matter of determining when the 
cells are exhausted, as there is no change in 
the outside appearance. 
There are instruments, known 
as ammeters, which enable 
one to determine how much current a dry 
cell will furnish ; and where many dry cells 
are used, this instrument should always 
be on hand to detect exhausted cells. If 
an instrument is not 
available, the strength 
of the cells must be 
judged from the size 
and character of the sparks produced when 
tested. 

Storage batteries make a very satis- 
factory source of electric current for igni- 
tion, but provision must be at hand for 
recharging when they become exhausted. 
Fig. 231. An oscii- Magnetos and Dynamos. Perhaps the 

lating magneto on ° J ± 

demonstration stand, most satisfactory source of electric current 
for gasoline engine ignition is the magneto or dynamo, 
which is a small instrument for making electricity by me- 
chanical means. Indications are that it will be only a 





230. A storag 
battery. 



FARM MOTORS 



359 



comparatively short time until the magneto will be consid- 
ered a necessary part of the equipment of the gas engine. 
At the present time the magneto is regarded as almost a 
necessity in the operation of the automobile engine. In 
selecting a magneto or dynamo, care should be taken to see 
that it is well adapted to the service required and that it is 
properly installed. 

Valve Action. The last df the four essentials for the suc- 
cessful operation of the gas engine is proper valve action, or 
the correct timing of the valves. It is obvious, after what 
has already been written 
on this subject, that the 
valves must open at the 
proper time to let the 
gases into the cylinder, 
close at the proper time 
to withhold them for the 
power stroke, and open 
again to let the burned 
gases escape. The suc- 
tion or inlet valve on 
farm engines is usually 
operated by the suction produced by the piston during the 
suction stroke, and, outside of the adjustment of the light 
spring which closes the valve, it is self -timing. The exhaust 
valve should open before the end of the expansion stroke, 
to allow the free escape of the burned gases, and must 
close at about the end of the exhaust stroke. The exhaust 
valve for an average-sized engine is made to open when 
the crank is about 30° from dead center, but the time will 
vary with the speed and size of the engine. Directions 
should be found with each engine for the setting of the 
valves. 




232. 



dynamo called the Auto- 
sparker. 



360 AGRICULTURAL ENGINEERING 

QUESTIONS 

1. Why is ignition so important to the success of a gas engine? 

2. Describe the hot-tube igniter. 

3. What are the names of the two systems of electric ignition? 

4. Describe the make-and-break system of ignition. 

5. Explain how this system may be tested. 

6. Describe the jump-spark system of ignition. 

7. Explain how this system may be tested. 

8. Describe the use of dry cells as a source of current for electric 
ignition. 

9. How does the dynamo or magneto furnish electricity for igni- 
tion purposes? 

10. Why is valve action or timing important? 

11. Describe in a general way when the inlet and exhaust valves 
should open and close with reference to the position of the crank. 



CHAPTER LVII 

SELECTING A GASOLINE OR OIL ENGINE 

The selection of a gasoline or oil engine for the farm is not 
easy, owing to the many features of the problem involved. 
First, there is the size or horsepower to be decided; second, 
the type, involving such features as weight and speed; third, 
the mounting; and fourth, the quality of the engine. 

The Size. The gasoline or oil engine is used on the farm 
for many purposes at the present time, and the power 
requirements for these various purposes differ widely. The 
following list gives the more common uses for the gasoline 
engine and indicates the approximate amount of power 
required : 

Washing machine, J^ to 1 H.P. 

Churn, 1 to ^ H.P. 

Pump, H to 2 H.P. 

Grindstone, H to 2 H.P. 

Electric generator, 1 H.P. or more. 

Feed mill, 3 H.P. or more. 

Portable elevator, 3 to 5 H.P. 

Corn sheller, 2 H.P. or more. 

Ensilage cutter, 5 to 25 H.P. 

Threshing machine, 6 to 50 H.P. 

It is to be noticed that the first four machines require a 
rather small engine, while the others either require consider- 
ably more power, or they may be operated more advan- 
tageously when of a size suitable to a medium-sized engine. 
The feed grinder may be obtained in almost any size; but 
where magazine bins are not provided and where it is expected 



362 AGRICULTURAL ENGINEERING 

to give the grinder attention while in operation, a large one is 
a decided advantage. A grinder using six to twelve horse- 
power will grind feed at such a rate that one man will have all 
he can do to provide grain for the hopper and to shovel 
away or bag the ground feed. 

Ensilage cutters, when provided with a pneumatic ele- 
vator or blower, require considerable power, and it is an 
advantage to have a machine which will take undivided 
bundles of fodder. To operate such a machine, a 12-horse- 
power engine, or larger, is required. 

There are small threshing machines on the market which 
require little power for their operation, and are no doubt a 
success where a small amount of grain is to be threshed. The 
small-sized machines, equipped with the modern labor-saving 
attachments, such as the self-feeder and the wind stacker, 
require about 12 horsepower for their successful operation. 
The other larger machines mentioned may be procured in 
almost any size to accommodate the size of the engine pur- 
chased. 

From this analysis it would seem that there are two classes 
of work on the average-sized farm which require two sizes 
of gasoline engines if the work is to be performed economic- 
ally. A certain portion of the fuel used by an engine is 
needed to overcome the friction within the engine itself, or 
to operate it. After enough fuel is furnished to keep the 
engine in motion, the additional fuel used is converted into 
useful work. The percentage of the total fuel required to 
operate the engine proper, when under full load, is not far 
from 25 per cent for average conditions. Thus it is seen that 
it will require much more fuel to operate a 12-horsepower 
engine empty, or under no load, than to operate a 1 ^-horse- 
power engine under full load. 



FARM MOTORS 



363 



The average farm well will not furnish water faster than 
it could be pumped with a small l*^- or two-horsepower 
engine; so a larger load cannot be provided by increasing the 
size of the pump or the number of strokes per minute. The 
question is often asked, when 
the purchase of an engine 
for pumping is contemplated, 
whether it would not be best 
to purchase a much larger 
engine than actually needed 
in order that it may be used 
for other work. If the pump- 
ing is to be continuous, that 
is, every day, it will be found 
more economical to buy a 
small engine to do the pump- 
ing and a comparatively 
larger one for the other work. 
This will be explained by 
the following calculation: 

Fuel per year for 1 ^-horse- 
power engine, light pumping load, 
2 hours per day, equals 0.2 gal- 
lons times 365, or 73 gallons. 

Fuel per year for 8-horse- 
power engine, light pumping load, 
2 hours per day, equals 0.45 gal- 
lons times 365, or 164.3 gallons. 

Difference equals 164.3 — 73, 
or 91.3 gallons. 

At 15c per gallon, 91.3 times 15c equals $13.69. 

This will more than pay for the interest on the cost of the 
smaller engine, and its depreciation. If the comparison be 




A special type of engine 
;ed for pumping. 



364 



AGRICULTURAL ENGINEERING 



made with a larger engine, the difference in the cost of oper- 
ation would be greater. 

The Type of Engine. The type of engine to select will 
depend largely on the kind of service required. If the engine 
is to be placed upon some horse-propelled machine, like the 
binder, to drive the machinery, a light-weight engine is 
highly desirable. Lightest weight may be secured by select- 
ing a high-speed two-stroke cycle engine. The four-stroke 




jasoline engine used to operate 
binder. 



the machinery of a grain 



cycle may be made quite light by introducing high rotative 
speed and using refinement in construction. Usually, high 
speed is conducive to increased wear and short life. Modern 
automobile design has, by improved methods and materials 
of construction, practically overcome the objections to the 
high-speed engine. 



FARM MOTORS 365 

The average farm machine does not require an extremely 
steady power, and for this reason the hit-or-miss governed 
engine is the most satisfactory for average conditions, on 
account of its simplicity and economy. Where an engine is 
used for electric lighting, the throttle-governed engine or an 
engine with extra-heavy fly wheels should be used. 

The Mounting. The stationary engine has many advan- 
tages over the portable engine in that it can be better pro- 
tected and, when mounted upon a good foundation, can per- 
form its work under the best conditions satisfactorily. The 
pumping engine should be a stationary engine; it may also 
perform such other work as may be brought to it. It will 
prove highly satisfactory to locate the pump house, the farm 
shop, and the milk house so as to enable the power from one 
engine to be used in all. 

The Quality. A poorly constructed and inadequately 
equipped engine is a bad investment at any cost. A gasoline 
engine should not only run and furnish power for a time, but 
it should be so constructed and of such material as to have a 
long life and require the minimum amount of attention and 
repair. In considering the purchase of an engine, cognizance 
should be given to the chief factor which causes the manu- 
facturer to build a high-grade engine, — namely, the desire to 
earn a reputation for building first-class goods. 

The vital parts of a gasoline engine, as of any machine, 
are those which wear and which must be adjusted and 
repaired. The following points are important : First, these 
parts should be provided with adequate lubrication, as it is 
the principal factor in reducing wear. Second, the size of the 
parts that wear should be of liberal dimensions and of a good 
quality of material. Third, the parts should be easily 
adjusted. Fourth, the parts should be easily replaced when 
worn out, 



366 



AGRICULTURAL ENGINEERING 



Testing. A brake test may be made of the engine to 
determine the amount of power it will deliver and the amount 
of fuel required per horsepower per hour. In addition to 




Fig. 2 35. A gasoline engine arranged for a test. The brake is on the 
back side. 



determining the power of the engine, if the test be continued 
for a time (two hours or longer) an examination may 
be made of the efficiency of the cooling system and of the 



FARM MOTORS 367 

ability of the engine to carry a full load without any over- 
heating of the bearings, or other disorders. 

Estimating Horsepower. The horsepower of a gasoline 
engine may be estimated from the diameter of the cylinder, 
the length of stroke, and the revolutions per minute. If these 
quantities are known for several engines, a comparison of their 
horsepower may be made. Such an estimate can only be 
considered approximate, however. 

A satisfactory formula for estimating the horsepower of 
gasoline engines of the four-stroke cycle type is as follows : 

D 2 L R* 
B.H.P. = ■ 

18,000 
where D = diameter of cylinder in inches. 
L = length of stroke in inches. 
R = revolutions per minute. 

For two-stroke cycle engines the formula should read as 

follows : 

D 2 LR 
B.H.P. = 

13,600 

Another formula which has been suggested for vertical 

tractor engines is: 

66 D 2 L Rf 
B.H.P. = 

1,000,000 

For horizontal engines the formula is made to read as 

follows : 

75 D 2 L R 
B.H.P. = 

1,000,000 
These formulas will agree very closely with the brake 
horsepower of tractor engines developed in public test. 



*E. W. Roberts. 
fW. F. MacGregor. 



368 AGRICULTURAL ENGINEERING 

In selecting an engine, the accessories are often given little 
attention, when they should be carefully inspected; and if 
the engine is not well equipped in the way of first-class acces- 
sories, they should be selected. 

The lubricating system should be permanently installed 
and so arranged as to give all working parts a liberal supply of 
oil. The multiple oil pump is to be highly commended in 
this connection. Exposed oil holes, which may become filled 
with dirt and grit, should be guarded against. 

Summary. The following outline is suggested to aid a 
purchaser in making a comparison of the merits and value of 
different engines. The information asked for in this outline 
should be so obtained from all the engines considered. 

Things to Consider in Selecting an Engine. 

Name of engine. 

Type — stationary or portable. 

Rated horsepower. 

Diameter of cylinder. 

Length of stroke. 

Revolutions per minute. 

Piston speed per minute. 

Calculated horsepower by formula. 

Cooling system. 

Frame — construction. 

Main bearings — construction, accessibility, and adjustment. 

Cylinder and piston — construction. 

Crank — const ruction . 

Gears — construction. 

Valves — construction and accessibility. 

Ignition system — construction and protection. 

Lubrication system — construction and completeness. 

QUESTIONS 

1. What are the principal features to be considered in selecting 
a gasoline or oil engine? 



FARM MOTORS 369 

2. What will determine the size to be selected? 

3. Why is it not economy to use a large engine for light work? 

4. How much power is usually required to operate a farm pump? 
A churn? A washing machine? A feed mill? A corn sheller? An 
ensilage cutter? A threshing machine? 

5. What should govern the type of engine to be selected? 

6. Where may a portable engine be used to advantage? 

7. What are some of the indications of quality in a gasoline or oil 
engine? 

8. Of what use would a test of the horsepower be? 

9. Explain how the horsepower of an engine can be estimated. 

10. A four-stroke cycle engine has a cylinder 8 inches in diameter; 
the stroke is 10 inches long and it operates at 360 revolutions per min- 
ute. Estimate its horsepower. 

11. What are some features to consider in selecting the accessories 
of an engine? 

12. Give a list of the parts that should be inspected in selecting a 
gasoline or oil engine. 

Note : — The instructor here should furnish the students with problems 
in the estimating of the horsepower of engines, perhaps measuring 
certain engines and comparing the estimated horsepower with manu- 
facturer's rating. 



CHAPTER LVIII 
THE GAS TRACTOR 

The Utility of the Gas Tractor. The gas tractor — and 
reference is here made to the tractor with the internal-com- 
bustion engine — has developed faster during the past ten 
years than has any other machine used on the farm. On the 
broad prairies, where the conditions are the most favorable 
for its use, it is rapidly taking first place over the horse; and in 
less favorable localities, where intertilled crops are grown, 
the gas tractor is being successfully tried out. All this has 




A tmall gas tractor plowing. It may be successfully- 
operated by one man. 



taken place despite the fact that ten years ago the gas tractor 
was an unusual sight. No one reason can be given for this 
increase in power farming. The new broad open fields of the 
West, the rapid development of the internal-combustion 



FARM MOTORS 



371 



engine, and especially the factor of economy, are suggestive 
causes. 

The tractor has been regarded as unwieldy in small fields, 
but this difficulty has been largely overcome by using the 
proper system in laying out the lands. One convenient sys- 
tem is to lay out the fields in lands of such widths as to lose 
little time in turning at the ends. A strip is left at each side 
of the field of a width equal to the turning strip at the ends, 
and sides and ends are turned last by p.lowing around the 
entire field. 

The tractor was first introduced for plowing, as this 
requires more power than any other kind of farm work; but it 
is also now being generally used in seeding and harvesting. 
In many instances several 
of these operations are 
carried on at the same 
time. 

A gas tractor consists 
of an engine, the transmis- 
sion, and the truck. These 
parts will now be discussed 
under separate heads. 

The Engine. The trac- 
tor engine does not differ 
materially from any other 
internal -combustion en- 
gine. No one type of engine has been generally adopted 
for traction purposes. However, nearly all are of the four- 
stroke cycle type. The differences in these motors lie in the 
number of cylinders, the speed of the engine, and the method 
of governing. 

The single-cylinder engine has a decided advantage in 
simplicity. It is easier to manage a one-cylinder than a two- 




The motor of an oil-burning 
tractor. 



372 AGRICULTURAL ENGINEERING 

cylinder engine. If the engine is not in proper adjustment 
there is no tendency to continue to operate it, as there is when 
there are two or more cylinders, letting the remaining ones 
furnish more than their share of the power. A multi- 
plicity of cylinders, on the other hand, for a given power, 
reduces the magnitude of the impulses and thus to a large 
extent relieves the gearing of severe shocks. The multiple- 
cylinder engine furnishes a steady power and is a little more 
agreeable to operate for that reason. There seems to be 
little doubt but that greater skill is required to keep the com- 
plicated engine in proper adjustment and 
repair. 

The Clutch. As the gas engine cannot 
be started under load, it is necessary to 
have a clutch to engage the engine with 
gears or with chains and sprockets that 
transmit the power to the drivers. This 

Fig. 23S. One form , , . . ... , , .. 

of clutch. The wood- clutch is generally used to engage a pulley 

en shoes are force;! . ., . . t ± i • ± _,• 

outward against the when the engine is used to drive a station- 

rim of the wheel, i • .,i 1 ix i xi x x* 

engaging it by fric- ary machine with a belt, when the traction 
tlon ' gearing is disengaged. 

In construction, the clutch consists of shoes usually made 
of wooden blocks, which, by suitable levers, are made to bear 
against a disk or other surface with sufficient pressure to 
cause the power to be transmitted through the parts in 
contact. The form and material of the friction surfaces 
vary widely. Sometimes the clutch takes the form of two 
cones, hence the name cone clutch. Again, the friction 
may take place between a series of disks, one-half of which are 
attached to the engine shaft and the other half to the trans- 
mission. This type of clutch is called a multiple-disk clutch, 
and the disks are usually engaged by the pressure of a spring 
which may be brought to bear at the most suitable time. 




FARM MOTORS 373 

The clutch is a vital part of the tractor and should be 
located as close to the engine as possible. The higher the 
speed at which the clutch rotates the smaller force it will have 
to transmit. 

The Gearing. The gears are an important part of the 
tractor. They should (1) be of liberal dimensions and of 
great strength; (2) be constructed of such materials as to 
resist wear to the greatest advantage; (3) be adequately lubri- 
cated and protected from dirt and grit. 

Change of Speed. Change of speed is especially desirable 
with light tractors and is quite necessary where the land is 
rolling. The load which any tractor will draw is limited by 
the load it is able to draw up the steepest incline. If a 
reduction of speed be made for inclines or hills a larger load 
may be carried continuously. 

A reverse in direction of travel or a change of speed is 
accomplished in two general ways : by sliding gears, which is 
the accepted method now used in automobiles; and by plane- 
tary gears. The former is the simpler method but is not so 
convenient of operation. 
Planetary gears take 
their name from the gears 
being fitted to a revolv- 
ing frame or spider. 

The Trucks. One of 
the most important parts 
of the modern tractor is drivins wheels - 

the truck, which consists of the frame and the steering and 
drive wheels. The frame is the backbone of the tractor, 
and to it are attached the bearings that carry the main axle 
and the shafts which support the gears. 

The Steering Wheels. Two methods of constructing the 
axle of the steering wheels are in common use. In one the 




The truck for a gas tractor, 
showing frame, gearing-, and steering and 



374 AGRICULTURAL ENGINEERING 

axle is pivoted at the center, and steering is accomplished by 
revolving the axle about this pivot or king bolt. The main 
advantage of this system is that the steering wheels may be 
turned while the tractor stands still. 

In the other style the axle is pivoted just inside of each 
steering wheel and each wheel is turned about its own pivot. 
This style of steering mechanism is easy to handle while in 
motion. It is quite positive, that is, there is no slack to take 
up in the chains, and it is of more rapid action than the other 
style. 

The Traction Wheels. The traction wheels should be 
carefully considered in making a selection of a tractor, because 
certain wheels are adapted to certain conditions. If the 
ground over which the tractor must pass be soft, it is highly 
desirable that both the drive and the steering wheels be as 
high as practical. Wheels of large diameter present a larger 
section of their periphery to the surface of the ground, and 
so cut in but slightly. Extensions are provided by all manu- 
facturers for making the drive wheels wider for work in 
soft ground. Where the soil is exceedingly soft, the cater- 
pillar tread or creeping grip should be used. It is possible to 
use this type of tractor in marsh or swamp soils or over sand 
where it is impractical to use horses. 

The Equipment. Too much emphasis cannot be laid upon 
the importance of securing a tractor which is well equipped. 
Often there is a serious loss of time resulting from the poor 
quality of parts that cost but a few cents. A purchaser 
should see that the tractor has modern high-class ignition, 
carburation, and lubrication systems. 

QUESTIONS 

1. What are some of the conditions under which the gas tractor 
can be used with economy? 



FARM MOTORS 375 

2. To what kinds of work is the present gas tractor adapted? 

3. What are some of the advantages and disadvantages of the 
multiple-cylinder engine for a tractor? 

4. Why is the clutch an important part of the gas tractor? 

5. Describe the differences in the shoe, cone, and multiple-disk 
clutches. 

6. Why is the gearing an important part of a gas tractor? 

7. How may a change of speed be accomplished? 

8. What is the purpose of the frame? 

9. Describe two styles of steering wheels. 

10. Discuss the construction of traction wheels. 

11. Why should the equipment of the tractor be given careful con- 
sideration? 



CHAPTER LIX 
THE STEAM BOILER 

The Steam Power Plant. A steam power plant consists 
essentially of two parts, the steam boiler, for generating steam 
by the combustion of fuel ; and the steam engine, which con- 
verts into work the energy contained in the steam. It is 
customary, however, to refer to the entire steam plant as the 
steam engine, when the plant is small. When the boiler and 
engine are mounted on wheels and arranged with suitable 
gearing for propelling itself as well as for drawing loads, the 
outfit is referred to as a traction engine. Of late years it 
has become customary to refer to the steam traction engine as 
the steam tractor. The subject of the steam power plant will 
be divided into three parts, confined to as many chapters, as 
follows: the steam boiler, the steam engine, and the steam 
tractor. At one time the steam engine as denned above and 
the steam tractor were the principal sources of power for 
agricultural purposes, when large units were required. The 
development of the internal-combustion engine and tractor 
has been more rapid in recent years than that of the steam 
engine and tractor. 

The Principle of the Steam Engine. The steam engine is 
a heat engine, in that its function is to transfer the heat pro- 
duced by the combustion of fuel, usually wood or coal, into 
mechanical energy. It might be styled an external-combus- 
tion engine, in that combustion takes place outside of the 
boiler proper and the heat is absorbed by passing the hot 
gases through tubes surrounded by water. 



FARM MOTORS 377 

In an open vessel water cannot be heated above the boil- 
ing point of 212° F., but heat continues to be absorbed and is 
used in the formation of vapor. Water under pressure boils 
at a higher temperature. Thus if the pressure inside the con- 
taining vessel were two pounds greater than atmospheric 
pressure, the boiling point would be about 228° F. Changing 
water into vapor increases its volume many fold. At atmos- 
pheric pressure the volume of the vapor is about 1700 times 
that of the liquid. At 100 pounds pressure the volume of 
the steam is about 240 times the volume of the liquid. Water 
vapor, or steam, is a colorless gas which obeys all of the laws 
of gases as far as expansion and change of temperature are 
concerned. 

Functions of a Boiler. The functions of a boiler are to 
absorb heat from the hot gases produced by the burning of 
fuel and to transmit it to the water contained within, causing 
it to vaporize into steam. The steam boilers used in agricul- 
tural plants and in traction engine service include the firebox, 
or furnace, which may be placed either directly underneath 
the main part of the boiler or entirely within it. 

Location of the Furnace. Boilers with the fire box out- 
side of the boiler proper are called externally-fired boilers. 
This type can safely be used for stationary work and are 
usually set in brick work, which forms a large part of the 
furnace. Those which have the furnace within the main 
body of the boiler, or shell, as it is called, are said to be inter- 
nally-fired boilers. Most of the boilers used in agricultural 
practice and all of the boilers used for traction engine service 
are internally fired. 

The Vertical Boiler. The vertical boiler is used in small 
units and where space is especially valuable. It consists of 
a cylindrical shell containing a furnace in the lower end, over 
which is placed a tube sheet or plate and a system of tubes. 



378 



AGRICULTURAL ENGINEERING 



These boilers are not considered very durable and are quite 

difficult to clean properly. 

The Locomotive Type of Boiler. The locomotive type of 
boiler is the one most generally used for trac- 
tion engine service. It consists of a fire box 
made of steel plates, in which the furnace is 
placed; a cylindrical shell extending forward, 
containing a comparatively large number of 
tubes; a smoke box at the front end; and a 
stack to carry the smoke away. 

The fire box is almost entirely surround- 
ed with water. The plate directly above the 
fire is called the crown sheet and the plates 




Fig. 240. A 
vertical boiler, 

vaive; '£, try forming the sides of the box are called side 

cocks; C, injec- , , x „ , 

tor; d, hand sheets. In some instances lire boxes are so 

hole; E, pressure 
gauge; F, gauge 
glass; G, fire 
door; H, ash 
door. 



made as to have water beneath the grates; 

such a boiler is said to have a water bottom. 

The boiler has a cylindrical chamber riveted 
to the top of the shell, in which the steam collects and from 
which it is drawn to the engine. This part is called the 
steam dome, and is a device for drying the steam. 

All parts of the boiler are made of the best steel plates, and 
the seams are carefully riveted together. The joints are made 




Fig. £41. A boiler of the locomotive type in section: A, steam dome; 
B, smoke box; C, fire box; D, grates; E, tubes; F, crown sheet. 



FARM MOTORS 379 

tight by calking or battering the edges of the seams down 
with a special tool designed for the purpose. The flat plates of 
the fire box are supported by bolts or studs running from one 
plate to the other. These are called stay bolts, except those 
over the crown sheet, which are called crown bolts. The 
boiler is usually provided with a valve at the lowest point, 
which may be opened to allow any sediment in the boiler to 
be blown out. 

In the management of the locomotive type of boiler, great 
care should be taken to keep the water over the crown sheet 
at all times. 

Return-Flue Boilers. The return-flue boiler has a large 
cylindrical shell in which a comparatively large flue is placed, 
large enough to contain t *** E % 

the furnace. The heated l^M 

gases pass to the front end 4^1 

tubes to the smoke box in ifess £u^— ; — - — -111 

the back end. One ob- ;i ~_ ' \ ^^^^ggggp^a^---, : 

jection to this type of boiler <M~^^^^^^^ ' jmz± 

is the limited amount of fllp^.""..:^-" ~" ~ ~ ~- ^ -*P^S^M 

grate Surface Which Can Fi §- 2i2 - A sectional view of a return- 
_ _ flue boiler. 

be provided. This type, 

however, is regarded as one of the safest, and is very eco- 
nomical in the consumption of fuel. 

Capacity of Boilers. The capacity of a boiler is usually 
designated in horsepower. Formerly this meant the capacity 
to supply enough steam for an engine of the designated 
horsepower. Now boiler horsepower means the capacity 
to absorb a certain amount of heat in a given time. The 
standard horsepower as established in this country is the 
capacity to evaporate 30 lbs. of water per hour into steam at 



380 AGRICULTURAL ENGINEERING 

70 lbs. pressure by the gauge from the feed water at a temper- 
ature of 100° F. 

It is easy to see, however, that the capacity of any boiler 
depends on its ability to burn fuel, or the area of the grate 
surface, and on the heating surface which will absorb the heat 
produced. Thus it is possible to estimate the capacity of the 
steam boiler from the size of the grates, allowing from % to }/% 
square foot for each horsepower. In like manner the horse- 
power may be calculated by determining the entire heating 
surface of the boiler, or the area of the plates and tubes which 
have heated gases on one side and water on the other, and 
allowing 14 square feet of heating surface for each horsepower. 

Quality of Steam. As steam leaves the boiler there is a 
tendency for it to carry water with it in the form of spray. 
It is the purpose of the steam dome to cause the water to 
settle from the steam as fast as possible. Steam which con- 
tains water in the form of spray is called wet steam, and the 
proportion of water to steam is sometimes called the quality 
of steam. Steam which does not contain any water is said 
to be dry steam. When dry steam is passed through highly 
heated tubes it is heated above the boiling point of water for 
the pressure under which the steam is confined. When in 
this condition the steam is said to be superheated. Some 
boilers are provided with superheaters for raising the tem- 
perature of the steam in this way. To prevent the loss of 
heat it is customary to cover the pipes leading the steam from 
the boiler to the engine with some non-conductive material in 
the shape of pipe covering. 

Boiler Accessories. All boilers must be provided with 
certain accessories, in order to permit of their successful 
operation and management. 

Gauge Cocks. Boilers are usually provided with two or 
three gauge cocks to enable the fireman to determine the 



FARM MOTORS 381 

height of the water within the boiler. If the gauge cock 
below the surface of the water be opened, a cloud of white 
vapor will be emitted; if the cock in connection with the steam 
space be opened, a colorless gas will escape. In this way 
the height of the liquid may be determined at any time. It 
is customary to put the lower gauge cock slightly above the 
level of the crown sheet or upper tubes. 

The Gauge Glass. In addition to the gauge cocks, the 
gauge glass is provided, which shows directly the height of 
the water in the boiler. Care should be taken to see that the 
gauge glass does not become clogged with sediment and thus 
fail in accuracy. The low water condition is reached when 
the water does not cover the heated plates of the boiler. 
Steam is not a good conductor of heat; so if the plates become 
uncovered they are quite sure to become so hot as to be 
softened and perhaps destroyed by the pressure of the steam. 
Low water is one of the common causes of boiler explosions. 

The Pressure Gauge. Another essential, accessory for the 
steam boiler is the pressure gauge. This instrument indicates 
the pressure of the steam within the boiler in pounds per 
square inch. The usual pressure gauge consists of a hollow 
brass tube curved to a circle, which tends to straighten as the 
pressure within increases. By connecting this tube with a 
needle over a graduated dial, by suitable mechanism, the 
pressure may be indicated directly. A siphon directly below 
the gauge prevents steam from entering and heating the tube 
and changing its elasticity. 

The Safety Valve. Every boiler should be provided with 
a safety valve, which will permit the escape of the steam as 
fast as generated, after a certain pressure has been reached, 
in order that the pressure shall not exceed the strength of the 
boiler. The usual safety valve is held closed by a spring 
which may be adjusted for the desired pressure. Care should 



382 



AGRICULTURAL ENGINEERING 




Fig. 243. A spring 
loaded safety valve. 



be taken to see that the pressure valve is kept in working 
order, and that it is not set too high for the strength of the 
boiler. It should also have sufficient capacity to release the 
steam as fast as it can be produced in 
the boiler under any condition. 

The Fusible Plug. As an additional 
safety device, a fusible plug, containing 
a core made of some metal with a low 
melting point, like tin, is placed at the 
highest point of the crown sheet which 
will be first exposed by low water. When, 
because of low water, the plate becomes heated, the soft 
metal core of the plug melts away, causing the steam to blow 
on the fire and put it out. 

The Boiler Feeder. In order to re- 
ceive additional water the boiler must be 
provided with some sort of feeder. One ^ 

such device is the cross-head pump, which p i U g, 'which is placed 

.,,. ,, , ,, i i <• in the crown sheet as 

is attached directly to the cross head of showI1 a t f in Fig. 
the engine and can be operated only when 
the engine is running. The independent pump has a steam 
cylinder of its own and may be operated by steam from the 
boiler. This type of pump is practically a small steam engine. 

Another form of boiler feeder is 
the injector, which takes steam 
from the boiler and, by allowing 
it to expand, converts its energy 
into kinetic energy. As this steam 
strikes a supply of cold water 
within the injector it condenses, 





Fig. 24E 



a standard type of but the impact drives the water 

injector. 



into the boiler. 
The Feed Water Heater. Many boilers are provided with 
feed water heaters which use the exhaust steam from the engine 



FARM MOTORS 383 

to heat the water as it is forced into the boiler. The heat 
thus saved may amount to as much as ten to fifteen per cent. 
Boiler Management. In managing the boiler care should 
be taken to see that the flues are kept free of soot, in order 
that the heated gases may come in direct contact with the 
metal, and that the boiler is kept clear of incrustation on 
the inside. Such accumulations do not have the heat-con- 
ducting properties of the steel and result in a serious loss of 
heat. If the scaly deposits from the water become too thick, 
the heat may not be carried away from the plate fast enough 
to prevent it from becoming overheated. Thus care should 
be taken not only to use water which is free from foreignsub- 
stances, but also to clean the boiler frequently. 




46. A feed water heater in which the water is heated by the 
exhaust steam. 

Foaming sometimes occurs in a boiler, due largely to the 
presence of dirt, alkali, grease, or other foreign matter. It 
causes a large amount of water to be carried away with the 
steam, and prevents the engineer from determining accu- 
rately the true level of the water. Great care should be taken 
in managing the boiler when foaming takes place. 

Low water in a boiler should always be guarded against ; 
and if at any time it should occur, the further generation of 
heat should be stopped and the boiler allowed to cool. It is 
inadvisable to try to remove the fire, as it is quite sure to 
increase its intensity. The best procedure is to cover the 



384 AGRICULTURAL ENGINEERING 

fire with ashes, earth, or even green coal. Do not try to feed 
more water into the boiler, as cold water is quite apt to crack 
the hot plates and the great amount of steam suddenly gen- 
erated may cause an explosion. The steam boiler under 
pressure contains a large amount of energy, and a boiler 
explosion is very disastrous. 

QUESTIONS 

1. What are the essential parts of a steam power-producing plant? 

2. Explain how heat is converted into power by the steam plant. 

3. What is the function of the steam boiler? 

4. What two general locations may be given to a furnace? 

5. Describe the vertical boiler and the conditions to which it is 
adapted. 

6. Describe the construction of the locomotive type of boiler. 

7. What is meant by a return-flue boiler? 

8. How is the capacity of a boiler designated? 

9. How may the horsepower of a boiler be estimated? 

10. What is meant by "quality of steam"? 

11. What is the use of gauge cocks and the gauge glass? 

12. What is the purpose of the pressure gauge? 

13. What is necessary to provide a boiler with a safety valve? 

14. Describe the use of the fusible plug. 

15. What is the purpose of the boiler feeder? 

16. What is the use of the feed water-heater? 

17. Describe in a general way the management of a steam boiler. 

18. What is meant by "foaming"? 

19. What should be done in case of "low water"? 



CHAPTER LX 



THE STEAM ENGINE 

Mounting. Steam engines used in agricultural work are 
usually mounted directly upon the boiler, making with the 
boiler a complete power plant, as in the case of a portable or 
traction engine. An engine mounted upon a masonry foun- 
dation is said to be a stationary engine. All such engines do 
not differ essentially in construction. 

Principle. The steam engine consists fundamentally of 
a cylinder containing a close-fitting piston. This piston is 
connected through a piston rod to a crosshead and in turn 
through a connecting rod to a crank on the engine shaft. The 
crosshead is operated between guides. The steam is admit- 
ted at the ends of the cylinder through valves contained 
within the steam chest. The proper 
action is given to the valves by an 
eccentric on the engine shaft, con- 
nected either to the valve rod, which 
extends into the steam chest in the 
case of a nonreversing engine, or to 
the reversing mechanism on a revers- 
ing engine. As steam enters the 
cylinder it pushes on the piston and 
causes it to move. After the piston 
has completed a part of the stroke, the valve closes, but the 
expanding pressure of the steam in the cylinder enables it to 
perform additional work on the piston. At the end of the 
stroke the steam is released, and the pressure is applied to the 
opposite side of the piston. This is all done automatically 




Fig. 24 7. A sectional view 
of the cylinder and steam 
chest of a simple engine. 



386 



AGRICULTURAL ENGINEERING 



by the valve mechanism, or valve gear, as it is called. The 
piston is fitted with rings which expand against the walls of 
the cylinder, making a gas-tight fit. The power developed 
by the engine is proportional to the travel of the piston in one 
minute and the average pressure of the steam on its face. 

Compound Engines. The compound engine has two 
cylinders. The steam is admitted first into the smaller one 
and allowed to expand to a certain pressure, and then it passes 
to the second, where it expands more fully. The compound 
engine enables the cylinders to be maintained at more nearly 




Fig. 24S. A sectional view of the cylinders and steam chest of 
a compound engine. 

the temperature of the steam. As steam expands, it cools ; 
and when fresh steam is admitted after the expansion of a 
cylinderful, some of it condenses, losing part of its power. 
Compound engines also tend to equalize the pressure of the 
steam on the piston throughout the stroke, giving a steadier 
motion and lowering the stress upon the working parts. 

The Double Engine. Many traction engines are pro- 
vided with two cylinders, making a double engine. The 
cranks are on the same shaft, but are located at an angle of 
90 degrees with each other, so that at no time can both cranks 



FARM MOTORS 



!87 



stop in line with the connecting rod, or be on dead center, in 
such a way that the engine cannot be started by the applica- 
tion of steam. 

The two-cylinder engines give a steadier motion but are not 
usually as economical in the use of steam as the single- 
cylinder engines, and are more expensive. 

The Fly Wheel. All steam engines and especially single- 
cylinder engines must be provided with a fly wheel to carry 
the engine over dead center, when the steam cannot act effec- 
tively upon the piston. It is customary to make this fly 
wheel in the form of a pulley, from which the belt 
may be run to other machines as desired. 

The Governor. The purpose of the governor is 
to maintain a uniform speed. The usual construc- 
tion of a governor is similar to that shown in the 
accompanying illustration. The fly balls are 
thrown outward by centrifugal force as they are 
rotated, thus gradually closing the valve through 
which the steam must pass. Governors may be 
adjusted for different speeds. . Fig. 249. 

' . y-y A common 

Lubrication. One important f ea- type of gov- 
ernor. 

ture of the operation of the steam 
engine is the lubrication of the piston, which 
is usually accomplished by admitting oil with 
the steam. The two devices in common use 
for feeding the oil uniformly are the oil pump 
and the lubricator. The oil pump is driven 
by the engine and is simply a small pump 
connected with a suitable reservoir for the oil. 
It can be adjusted to feed oil at any specified 
rate. The best kinds have a sight feed device, which 
enables the engineer to see the rate at which the pump is 
feeding the oil. 





Pig. 250. A 
sight -feed lubri- 
cator. 



388 AGRICULTURAL ENGINEERING 

The lubricator consists of a tank of oil connected under- 
neath with a short column of water. The excess weight of 
water over that of the steam when applied at the bottom of 
the oil reservoir enables the oil to be fed through a small 
valve, a drop at a time. The accompanying illustration 
shows the construction of a lubricator. 

QUESTIONS 

1. How is the farm steam engine usually mounted? 

2. Explain the principle of the steam engine. 

3. Describe the compound engine, and what advantage does it 
offer? 

4. What are the merits of a double engine? 

5. Why is it necessary for a steam engine to have a fly wheel? 

6. Describe the action of the governor. 

7. Describe the action of the steam engine lubricator. 

8. What other oiling device is in common use? 



CHAPTER LXI 
THE STEAM TRACTOR 

A steam boiler and engine mounted upon skids or on a 
truck to permit them to be moved from place to place make 
what is called a portable steam engine. If an engine be pro- 
vided with means of ready control and with gearing for trans- 
mitting the power to the traction wheels, thus enabling it to 
propel itself forward over the ground and perhaps pull a load 
after it, the outfit is called a steam traction engine, or a steam 
tractor. The latter term has come into use recently. 

The steam boiler and the steam engine have been dis- 
cussed under separate heads. This chapter will be devoted 
to a discussion of the features of the steam tractor other than 
the boiler and the engine. 

The Mounting of the Boiler. There are two general types 
of mounting for the steam tractor boiler. One has a frame 
connecting the traction and steering wheels in such a manner 
as to form a truck sufficiently strong to support the boiler. 
As now generally manufactured this is called the under- 
mounted tractor, but a general name for this style of construc- 
tion is frame mounted. 

Again, the boiler may be used as the frame for the engine 
and the truck, in which case the gearing is attached to the 
boiler by brackets or flanges riveted to the boiler. This 
construction, called top mounting, is in more general use, but 
is criticised by some because the boiler is subject to the 
stresses produced in transmitting the power from the engine 
to the traction wheels. When the traction wheels are 



390 



AGRICULTURAL ENGINEERING 



mounted on brackets attached to the side of the boiler, the 
boiler is said to be side mounted. 

When an axle is provided for the traction wheels and it is 
placed to the rear of the boiler, it is said to be rear mounted. 
As it is quite impossible to keep the traction wheels in the 
side-mounted engine perfectly true, the rear-mounted form 
is generally recognized as being the more preferable of the two. 
Any wear or spring at the outer ends of the axles will allow the 




Fig. 251. An under-mounted double-cylinder steam tractor. 



wheels to approach each other at the top and to spread at the 
bottom, thus throwing the gearing out of alignment. 

Some rear-mounted boilers have the main axle mounted 
with radius arms, that the boiler may be carried on springs 
and still permit the gearing to be in proper mesh at all times. 

The Mounting of the Engine. The usual method of 
mounting the engine is to attach it to brackets or flanges 
riveted to the top of the boiler proper. This construction is 
generally referred to as top mounting. 

As previously mentioned, another type of construction 
provides a frame sufficiently strong to carry the boiler and 



FARM MOTORS 



391 



engine. In this case the engine is placed underneath the 
boiler, and is styled under mounted. This construction 
relieves the boiler of all stress due to the transmission of 
power and places the engine where it may be attended by 
the engineer standing on the ground. 

The Steering Wheels. The steering wheels of the steam 
tractor engine are generally mounted on an axle which 
may be turned by means of a hand wheel and a worm gear. 




Fig. 252. A top-mounted steam tractor. 

By turning the hand wheel a chain attached to one end of the 
axle is shortened, while another at the other end is lengthened. 
In large engines the power for steering is often supplied by a 
separate engine or is derived from the main engine by 
friction clutches. 

The Traction Wheels. The traction wheels of a steam 
tractor are important features of the outfit when the tractor 
is to be used for drawing loads or machines. The supporting 
power of the wheels depends upon the diameter of the wheel 



392 AGRICULTURAL ENGINEERING 

and the width of the tire. On soft ground, it is customary to 
provide an extra width of tire in the form of extensions, which 
may be removed when not needed. 

In order to grip the surface of the soil sufficiently, the 
traction wheels must be provided with cleats, lugs, grouters, 
or spikes, which grip the soil and enable the tractor to exert a 
greater tractive force. The form of these lugs should be 
adapted to the conditions under which they work. 

Rating. The size or capacity of the steam tractor is 
designated in horsepower. Formerly it was customary to 
indicate its tractive power in terms of horses. This rating 
has since become known as nominal rating, and is being 
superseded largely by the brake horsepower rating, which 
indicates the most practical power output of the engine 
proper. This rating is ordinarily about three times the 
nominal rating. 

A large part of the power of the engine is used in propelling 
the tractor and in overcoming the friction of the gearing. 
The tractive efficiency of a tractor is the ratio between the 
power furnished by the engine and the power delivered at the 
draw bar. Ordinarily this is about 50 per cent, but on soft 
ground it may run as low as 35 or 40 per cent. On hard roads 
it may be much higher than 50 per cent. 

Control. The control of the steam tractor is placed (1) in 
a throttle, through which the admission of steam to the 
engine is controlled; (2) in the reverse, which controls the 
direction of rotation of the engine; and (3) in a clutch similar 
to that described for gas tractors which connects the engine 
to the transmission. Some steam tractors have a brake by 
which the tractor may be held in place. 

The Clutch. The clutch on a steam tractor universally 
operates within the fly wheel of the engine. The friction 



FARM MOTORS 393 

shoes used are made of wood, and are forced out against the 
rim of the fly wheel by suitable linkage. 

The Differential. In order to permit the tractor to turn 
corners, or change direction a mechanism must be introduced 
which will allow one traction wheel to travel faster than the 
other. This mechanism is called the differential. There are 
two types of differentials, the bevel gear and the planetary. 

The Gearing. The gearing of a steam tractor is an 
important part of the outfit, especially when the tractor is 
used for direction purposes. It is now customary to make 
the gears very ample in size and of material which will resist 
wear to the greatest extent and still be capable of resisting 
the sho cks which must necessarily come upon them. Further- 
more, the tractor should be provided with means of excluding 
dust and grit from the gears, and with a system of lubrication 
that will at all times keep the gears amply lubricated. 

QUESTIONS 

1. Discuss the different types of boiler mounting. 

2. Explain two ways of mounting the engine. 

3. In what two ways may large tractors be steered by power? 

4. What are some of the important features in the construction of 
the traction wheels? 

5. What is the purpose of the cleats on the drive wheels? 

6. How is the power capacity of a steam tractor designated? 

7. How is a steam tractor controlled? 

8. What is the purpose of the differential gearing? 

9. Why is the gearing of a steam tractor worthy of careful atten- 
tion? 

LIST OF REFERENCES 

Instructions for Traction and Stationary Engineers, William Boss. 
Farm Engines and How to Run Them, James H. Stephenson. 
Farm Machinery and Farm Motors, J. B. Davidson and L. W. 
Chase. 



394 AGRICULTURAL ENGINEERING 

Power and the Plow, L. W. Ellis and Edward A. Burnley. 
Physics of Agriculture, F. H. King. 
The Gas Engine, F. R. Hutton. 
Gas Engine Principles, Rodger B. "Whitman. 
Farm Gas Engines, H. R. Brate. 

The Use of Alcohol and Gasoline in Farm Engines. U. S. Dept. 
of Agr. Farmers' Bulletin 277. 



PART SEVEN— FARM STRUCTURES 



CHAPTER LXII 
INTRODUCTION; LOCATION OF FARM BUILDINGS 

The study of farm buildings is important to those engaged 
in agricultural pursuits, for the following reasons : 

1. The amount of capital invested in farm buildings is 
large. 

2. Convenient farm buildings conserve labor. 

3. Comfortable buildings for live stock conserve feed and 
insure maximum production. 

4. The health of farm animals and the quality of the 
products produced by them depend in a large measure upon 
the sanitation, ventilation, and lighting of the farm buildings. 

Capital Invested in Farm Buildings. The fixed capital of 
farms is divided by the 1910 Census into land, buildings, 
implements, machinery, and live stock. The relative impor- 
tance of these is shown by the percentage which each bears to 
the whole. 

Land 69.5 per cent 

Buildings 15.4 per cent 

Live stock 12.0 per cent 

Implements and machinery 3.1 per cent 

Conservation of Labor by Convenient Arrangement of 
Farm Buildings. It is difficult to estimate the saving of labor 
which will result from buildings convenient in themselves and 
in their relation to one another. This, however, is an impor- 
tant matter, because the loss on account of inconvenience is 
accumulative, and the aggregate for a year is large. Thus 



396 AGRICULTURAL ENGINEERING 

the total distance covered in a year in walking 300 feet and 
return four times a day is over 145 miles, and a saving of 
30 minutes every day for a year is equal to nearly 19 days 
of ten hours each. As far as possible the arrangement of farm 
buildings should follow the principles incorporated in modern 
shops and factories. 

Comfortable buildings conserve feed to such an extent 
that under modern conditions it is practically impossible to 
produce meat or dairy products profitably without them. It 
is true that authorities differ on this point. Some maintain 
that protection from temperature changes is not of great im- 
portance for successful beef production, but all agree that 
protection from wind and wet is essential. Sanitary farm 
buildings maintain the health of farm animals. Pure air is 
as essential as good food. Poor ventilation furnishes the 
best conditions for disease germs to flourish, while proper 
lighting dispels disease by destroying germs. The best 
quality of milk cannot be produced in unsanitary barns. 

Laying Out the Farm. By the laying out of the farm is 
meant the arrangement and location of the fields, buildings, 
and lots. This is a subject which naturally precedes the 
arrangement and design of farm buildings, for it is well-nigh 
impossible to consider one farm building fully without taking 
into account its relation to other buildings and to the fields 
of the farm on which it is located. 

The proper arrangement of a farm is fundamental in 
securing convenience, system, and economy in its operation 
and management, and may determine the success or failure 
of the enterprise. 

In laying out the farm an almost endless number of condi- 
tions must be considered, among which may be mentioned: 

1. The amount of good and poor land. 

2. The location of the hills. 



FARM STRUCTURES 



397 



3. The location of the woodland. 

4. The location of water. 

5. The natural drainage. 

6. The original shape of the tract. 
The features to be desired are : 

1. Convenience of access, economy of fencing, and con- 
venience of rotation, of the fields. 

2. Convenience of relation to one another, to the fields, 
to the lots, and to the highways, of the buildings. 

A map of the farm showing location of buildings, lots, 
fields, streams, roads, and draining is very helpful. Each 



f\ Poor 

flRRRNGELMFNT. 
Legend: 

From Town ■*,.-.-, 
Mominq Work — 



Potatoes. 



To Fi d ds + + + 4 + + t i 



\&<$<3<3 (SGROVES ^ 8 S (J<5 
" 7<53 <J> <3C9<u}C3 43 © t3 <8 «a 
"- <i <S CSlil W <3 t3 S3 <3 ^a « 




K> i?t3fc3«J0e3 (5«<a <y is <a <a aa <a<3 
a <3 <3 eaeeQR OVE «> © «3 ©<« o 



/fH l_l l«* SH M 

/ Gbrnrrv 



1 



GrRRDEN 



Fig. 253. An inconvenient arrangement of farm buildings. 



field should be designated by a particular name or number 
and the exact acreage indicated. Such a map is extremely 
useful in planning the operations of the farm, the rotations, 
and in calculating the amounts of fertilizers, seed, etc. 



398 



AGRICULTURAL ENGINEERING 



To illustrate the great differences to be observed in farm- 
stead plans, attention is called to the two accompanying 
sketches. The first of these (Fig. 253) is the plan of a farm- 
stead just as it is at the present time. To do the morning 
chores on this farm, — tending to the horses, cows, and hogs — 
it is necessary to walk 2400 feet outside of the buildings. 
Besides this bad feature notice how inconveniently the garden 

is placed from the 
house. The well, also, 
instead of being be- 
tween the house and 
barn, is beyond the 
barn. 

Compare this plan 

with the next. The 

house is 150 feet from 

the road and the barn 

200 feet from the 



A GOOD 

flRRRNGEMENT . 

from Town « 
Morftinq Work - 
To Fields •-.. 



Cows 



Horses. 







IS 



PlJBUO 



HvOHWRY. 



Fig. 254. A good arrangement of farm 
buildings. The lines of travel in doing the 
work of the farm are indicated. 



house, which is not too 
close when located in 
the right direction. 
The prevailing winds 
are either from the 
northwest or south- 
east, and the odors 
from the barn are seldom carried toward the house. The 
implement and wagon shed also includes the shop and 
the milkhouse. If the well could be located near this shop, 
so much the better, as at this point a gasoline engine could 
be used to do all the light work. In doing the morning work, 
a man needs to walk only 900 feet, a saving of 1500 feet 
over the former plan. 



FARM STRUCTURES 399 

Principles of Location. In locating the farm buildings, it 
is well to incorporate as many as possible of the following 
principles in the plan : 

1. Have the buildings near the center of the farm, giving 
due consideration to other advantages. 

2. Needless fences should be avoided, on account of first 
cost and the cost of maintenance. 

3. A pasture should be adjacent to buildings. 

4. The buildings should occupy the poorest ground. 

5. The buildings should be located with reference to the 
water supply. 

6. The buildings should be on a slight elevation when- 
ever possible. 

7. A southwest slope is desirable. 

8. The soil on which buildings are to be placed should 
be dry and well drained. 

9. A timber windbreak should be secured. 

10. A garden plot should be near the house. 

11. The buildings should not be located on high hills, 
because of difficulty of access from fields and roads. 

12. The buildings should not be placed in low valleys, 
on account of the lack of air and good drainage and the 
danger from frost. 

13. The buildings should be located on the side of the farm 
nearest the school, church, or town. 

14. The house should not be less than 100 feet from the 
highway. 

15. The barn should be about 150 to 200 feet from the 
house, and not in the direction of the prevailing winds. 

16. The barn should be in plain view from the house. 

17. The lots should be on the farther side of the barn 
from the house. 

18. Several views from the house are desirable. 



400 AGRICULTURAL ENGINEERING 

19. All buildings should serve as windbreaks. 

20. The shop and machine shed should be convenient to 
the house, the barn, and the fields. 

Two general systems of arranging farm buildings have 
been developed in this country. For want of better terms, 
they may be designated as the distributed system, in which a 
separate building is provided for each kind of stock or for 
each purpose to which it may be devoted; and the concen- 
trated system, in which everything is placed under one roof as 
far as possible, or the buildings are at least connected. The 
advantages of the first system may be stated as follows : 

1. A greater amount of lot room is possible. 

2. Different kinds of animals are separated. 

3. There is less destruction in case of fire. 

4. It is more economical for the storage of certain crops 
and machinery. 

5. Better lighting is secured: wide barns are necessarily 
dark. 

In turn, the following arguments may be advanced for the 
concentrated system: 

1. The first cost is less: needed space is secured with the 
minimum of wall surface. 

2. There is less expense for maintenance. 

3. It is more economical of labor. 

4. Better fire protection can be provided. 

5. Manure can be handled to the best advantage. 

6. It provides a very imposing structure. 

It is to be expected that opinions and tastes will differ, as 
well as conditions, and all of these will determine the best 
arrangement for any particular location. Most farmsteads 
are the result of growth and development, and for this reason 
are not what they would be if built entirely at one time. As 
changes are made and new buildings constructed it is well to 



FARM STRUCTURES 401 

keep in mind the desired features and to approach the ideal as 
far as possible. 

In commercial life it has often been found a matter of 
good business to dismantle certain buildings designed for 
manufacture and entirely rebuild them. There are, no doubt, 
many farms so equipped that it would be a good business 
investment to entirely dismantle the existing buildings and 
rebuild in such a way as to insure a more economic operation. 

QUESTIONS 

1. Give four reasons why the study of farm structures is impor- 
tant. 

2. What percentage of the fixed capital of the farm is invested in 
farm buildings? 

3. Explain how a convenient arrangement of farm buildings con- 
serves labor. 

4. In what way will comfortable buildings conserve feed? 

5. How is the quality of dairy products influenced by the character 
of the farm buildings? 

6. Upon what general conditions will the layout of the farm depend? 
7 What are the principal features to be desired in the layout of 

a farm? 

8. What are some of the principles involved in laying out the farm? 

9. Discuss the distributed system of farm buildings. 
10. Discuss the concentrated system of farm buildings. 



CHAPTER LXII1 
MECHANICS OF MATERIALS 

Definitions. Mechanics is that science which treats of 
the action of forces upon bodies and the effects which they 
produce. 

Statics is that division of the science of mechanics which 
treats of the forces acting on a body at rest, or in equilibrium. 
In architectural design, statics is the principal branch of 
mechanics to be considered, as nearly all the forces involved 
are those of rest. 

Action of a Force. A force acting upon a body tends to 
produce motion in two ways: 

1. It tends to produce motion in the direction of the 
force. 

2. If a point of the body be fixed, it tends to produce 
motion about that point. 

Condition of Equilibrium. Since a force acting upon a 
body tends to produce motion in two ways, the following 
conditions must be filled in order that equilibrium exist : 

1. The resultant of all the forces tending to move the 
body in any direction must be zero. 

2. The resultant of all the forces tending to turn the body 
about any point must be zero. 

The moment of a force about a point is the product of the 
force into the perpendicular distance from the line of the 
force to the point. 

Moments tending to produce clockwise rotation are called 
positive moments, and those tending to produce counter- 
clockwise motion, negative moments. 



FARM STRUCTURES 



403 




Tension 
Fig. 255. A 
sketch illustrat- 
ing a tensile 
stress. 



-ten- 



Equilibrium of Moments. The forces acting upon a body 
are in equilibrium when the algebraic sum of their moments 
about any one point is equal to zero. 

Stress. A stress is the resistance offered by a rigid body 
to an external force tending to change its 
form. A rope suspending a weight is under 
stress. If a section of the rope be taken at 
any point, the force exerted by the part of the 
rope on one side of the section on the part on 
the other side to prevent the rope from part- 
ing or breaking, is termed the stress at a section. 
The word strain is often used incorrectly for 
stress, but strain is the change of form pro- 
duced by a stress. Simple stresses are of three kinds, 
sile, compressive, and shearing. 

Stresses are measured in pounds or tons in countries using 
English units. The pound is the more often used. 

Tensile stresses are those tending to pull 
the object or material in two, or to stretch it. 
A rope suspending a weight is under a tensile 
stress. A tie rod in a truss is subjected to 
tensile stress. 

Compressive Stresses. Compressive stresses 
are those tending to crush the object or ma- 
terial, as the load that is placed on a column 
or on a foundation. 

Shearing Stresses. Shearing stresses are 
those tending to slide one portion l t fi -, - h — , T fc — , , 
of the material over another, or Fig 257 A sketch ilUlstrat . 
when there is a tendency to cut. in » a shearing stress. 

The stress on riveted joint is a good example. 

Complex Stresses. Complex stresses are those formed 
by a combination of simple stresses. The stresses in beams 
are usually complex. 




Compression 



Fig. 256. J 
sketch illustrat 
ing a compres 
sive stress. 



404 AGRICULTURAL ENGINEERING 

Unit stress is the stress per unit area. Stresses are 
usually measured in pounds, and areas in square inches. The 
total stress divided by the area of cross section in square 
inches will give the unit stress. 

S ~ A 
when P = total stress in pounds. 

A = area of cross section in square inches. 
S = unit stress. 

This rule is applied only when the total stress is uniformly 
distributed and the stress is a simple stress. 

Elasticity. Most bodies when subjected to a stress will 
be deformed. The amount the body is changed in shape is 
termed the deformation. An elastic body will regain its 
former shape when a stress is removed, if it has not been too 
great. Up to a certain limit the amount of change in shape is 
proportional to the stress. If the unit stress be increased to 
such an extent that the material will not regain its original 
shape after being deformed, the stress has passed beyond the 
elastic limit of the material. 

Ultimate Strength. If the unit stress of any material be 
increased until rupture or breakage occurs, the stress pro- 
ducing the failure is the ultimate strength of the material. 
If the failure be produced by the tensile stress, the ultimate 
tensile strength is obtained. In like manner the ultimate 
compressive and shearing strengths are obtained. The 
breaking load divided by the original cross section gives the 
ultimate strength. 

Working Stress. The greatest stress allowed in any part 
of a framed structure is called the working stress of that part. 
In turn, the working strength of a material to be used for a 
certain purpose is meant the highest unit stress to which 
the material ought to be subjected when so used. 



FARM STRUCTURES 



405 



Factor of Safety. The factor of safety is the ratio of the 
ultimate strength to the working stress of a material. 

f-S 

s 
when S = ultimate strength, s = working strength, f = factor of safety. 

The engineer in charge of design is called upon to decide 
the factor of safety to be used. 

The factor of safety should (1) be much below the elastic 
limit, (2) be larger for varying loads, (3) be larger for non- 
uniform materials. 

Factors of safety for various materials. 



Materials 



For steady 

stress. 
Buildings 



For varying 
stress. 
Bridges 



For shocks. 
Machines 



Timber 

Brick and stone 

Cast iron 

Wrought iron. . 
Steel 



15 
6 
4 
5 



10 

25 

15 

6 

7 



15 
30 
20 
10 
15 



This table is taken from an architect's handbook, and the 
factors of safety here recommended are nearly twice as large 
as are commonly used in designing farm structures. 

QUESTIONS 

1. Define mechanics. Define statics. 

2. In what two ways does a force acting on a body tend to produce 
motion? 

3. What are the two conditions for equilibrium? 

4. Define moment of force. 

5. When does an equilibrium of moments exist? 

6. Define stress. Define strain. 

7. Describe a tensile stress. A compressive stress. A shearing 
stress. A complex stress. Define unit stress. 

8. Explain what is meant by the elastic limit of a material. 

9. Define ultimate strength. Working stress. Factor of safety. 
10. Upon what conditions will the size of the factor of safety depend? 



CHAPTER LXIV 

MECHANICS OF MATERIALS AND MATERIALS OF 
CONSTRUCTION 

The Strength of Beams. The strength of a beam or its 
ability to support a load depends upon three principal factors : 
(1) The way the beam is stressed, or the way the load is 
applied or distributed and the beam supported; (2) the way 
the material is arranged; and (3) the kind of material. These 
factors are represented by the maximum bending moment, 
the modulus of section, and the modulus of rupture. 

The Bending Moment. The bending moment is a meas- 
ure of the stresses acting on a beam. Suppose a beam to be 
fixed solidly at one end, as would be the case if it extends 
into a solid wall, and a load or a weight to be suspended at the 
extreme end, as shown in Fig. 258. It is to be noted that the 

greatest stress in the beam would 
be at the point where it enters 
the wall. The force would tend 
to rotate the beam about a point 
in the beam where it enters the 
a cantilever iam,'* fbl&m wall. The stressesproduced would 
tnf^forofa y .oad 0n a e t e the'f a r n ee tend to pull the material in two 
end " at the upper side and to crush it 

on the lower. If the weight be placed somewhere between 
the wall and the end, the stress on the beam would be less 
than in the first instance; in fact, the stress would be in direct 
proportion to the distance from the wall to the weight. The 
stress would also be in direct proportion to the size of 
the weight. Thus the tendency to break the beam, or the 





FARM STRUCTURES 407 

stress at the wall, would be twice as great for a 20-pound 
load as for a 10-pound load. It is to be noticed that the stress 
would be greater at the point where the beam enters the 
wall than at any other point; or, in other words, the maxi- 
mum bending moment would exist at that point. 
Expressed in the form of a formula: 

B M = W L 

where B M is the maximum bending moment, W the weight, and 
L the length of beam in inches. 

If the beam be supported at 
both ends or extend into the wall 
at both ends, the maximum bend- 
ing moment would have an entire- 
ly different value; thus, for a tJ&A . A o£2^K2d3[ 
beam resting in supports at both the center of a simple beam - 
ends with a load at the center, 

BM=MWL 

If the load be uniformly distributed over the beam, then 
B M = y 8 W L 

The Modulus of Section. It is generally known that a 
2x4 piece of wood will support a greater load when placed on 
edge than when laid flat. The modulus of section is simply 
a measure of the strength of a beam according to the arrange- 
ment of the material. Thus, for a beam with a rectangular 
cross section, 

bd 2 

M S = — 
6 

where M S is the modulus of section, b the width of the beam in 

inches, and d the depth of the beam in inches. 

Thus it is seen that a 2x4-inch beam is twice as strong 

when set on edge as when laid on the flat; for, when placed 

on edge, 

bd 2 2X(4X4) 32 

M S = — = -= — 

6 6 6 



408 



AGRICULTURAL ENGINEERING 



If placed on the flat, 

bd 2 4X(2X2) 16 

M S = — = =— 

6 6 6 

or just one-half of the value previously obtained. 

The Modulus of Rupture. The modulus of rupture is a 
measure of the strength of the material to resist transverse 
or bending stresses. Thus oak is stronger than pine. The 
modulus of rupture is obtained by test. The following table 
furnishes the values of the modulus of rupture quite generally 
used. All of the values are per square inch of cross section. 

White pine 7,900 

Yellow pine 10,000 

Oak 13,000 

Hickory 15,000 

Cast iron 45,000 

Mild steel 55,000 

Formula for Beams. The general formula for beams may 

now be stated as follows: 

modulus of selection X rupture modulus 

Bending moment = : — ; : — — 

i actor oi satety 

This formula may be used in calculating the strength of 
beams, but it is given here principally to explain how the 
strength of beams varies. The following tables give the 
strength of columns or posts and of beams. 

Safe Strength of White Pine Beams. The following 
table gives the safe loads for horizontal, rectangular beams 









Span in 


feet 






Depth of 














beam 
















6 


8 


10 


12 


14 


16 


6 


720 


540 


432 


360 


308 




7 


980 


735 


588 


490 


420 




8 


1280 


960 


768 


640 


548 


480 


10 


2000 


1500 


1200 


1000 


857 


750 


12 


2880 


2160 


1728 


1440 


1234 


1080 


14 


3920 


2940 


2352 


1960 


1680 


1470 



FARM STRUCTURES 



409 



one inch wide with loads uniformly distributed. If the load 
be concentrated at the center, divide by two. 

For oak or Northern yellow pine, the tabular values may 
be multiplied by 1%; f° r Georgia yellow pine, by 1%. 

For a discussion of the materials used in the construction 
of farm machinery, see Chapter XXXI. 

Safe Load in Pounds for White Pine or Spruce Posts.* 



Size of post 


Length of post in feet 


in inches 


8 


10 


12 


14 


16 


4x4 

4x6 

5}4 round. 

6x6 

6x8 

6x10 

7}4 round. 

8x8 

8x10 

8x12 

9}4 round. 

10x10 


7,680 

11,520 

12,350 

19,080 

25,440 

31,800 

24,220 

35,450 

44,320 

53,180 

40,000 

62,500 


7,033 
10,550 
11,730 
18,216 
24,290 
30,360 
23,380 
34,300 
42,480 
51,450 
39,000 
55,400 


6,533 
9,800 
11,180 
17,352 
23,140 
28,920 
22,540 
33,150 
41,440 
49,730 
37,860 
53,960 


8,700 
10,490 
16,490 
21,980 
27,480 
21,660 
32,000 
40,000 
48,000 
36,800 
52,520 


15,620 
20,830 
26,040 
20,820 
30,850 
38,560 
46,240 
35,730 
51,080 



Oak and Norway pine posts are about one-fifth stronger, 
and Texas pine and white oak are one-third stronger. 

Stone. Limestone and sandstone are the kinds of stone 
generally used for building purposes. Granite is used to a 
limited extent. Limestone is the most common stone used, 
and when dense and compact is very durable. It often con- 
tains certain substances which cause the stone to become 
badly stained after being in use for a time. Limestone has 
an average compressive strength of about 15,000 pounds per 
square inch and weighs from 155 to 160 pounds per cubic foot. 



*Kidder's Pocket Book. 



410 



AGRICULTURAL ENGINEERING 



Sandstone of a good grade is an excellent building mate- 
rial. It has a strength of about 11,000 pounds per square 
inch and weighs about 140 pounds per cubic foot. 

The densest and strongest stones are the most durable, as 
a rule. A good stone will not absorb more than 5 per cent 
of its weight of water when soaked in water for 24 hours. 

Brick. Brick is a material quite generally used over the 
country, and when of a good quality is quite satisfactory. 
Brick should be of uniform size, true and square, and when 
broken should show a uniform and dense structure. Good 
brick will not absorb moisture to an extent greater than 10 

per cent of its weight, 
and the best will absorb 
less than 5 per cent. 
The crushing strength 
of brick should exceed 
4000 pounds per square 
inch. 

Hollow clay blocks 
or tile are made of the 
same material as brick, 
and should have the same characteristics. Clay blocks are 
lighter than brick, and so the cost of shipping is less. They 
cost less by volume, and more wall can be laid in a given time 
than with common brick. 

Lime. Lime is used in mortar where the greater dura- 
bility and strength of cement mortar are not needed. Quick 
lime should be in large lumps and should be free from cinders 
and dust. When slackened with water it should form a 
smooth paste without lumps or residue. Lime mortar is 
usually made of 1 part of lime to 2 or 3 of sand. 

Portland Cement. Portland cement is now generally used 
in the making of mortar and concrete. It should be finely 




Fig. 260. Hollow clay building' blocks. 



FARM STRUCTURES 



411 



ground and should set or harden neither too quickly nor too 
slowly. It should show a high tensile strength when hard- 
ened and sufficiently aged. It should not check, crack, or 
crumble upon hardening. Where cement is to be used in 
considerable quantities it should be carefully tested by 
standard tests. 

Sands. Sand should be clean, durable, coarse, and free 
from vegetable and other foreign matter. Coarse sand is 
preferable to fine sand because the percentage of voids or 
open space between the sand grains is less. 

Concrete. In a general way concrete consists of mortar 
in which there is imbedded more or less coarse material, like 




3JA/0 



STOMf 



COA/C/?£T£ 



Fig. 261. Material required to make concrete to the proportion of 
1 part of cement, 2 parts of sand, and 4 parts of broken stone. 

gravel or broken stone, called the aggregate. Thus it is seen 
that if the aggregate be good, durable material and the mortar 
be sufficient in quantity to surround all of the aggregate, the 
whole will be as strong as the mortar. In preparing concrete, 
therefore, it is desirable to obtain as dense a mixture as is 
practical. 

The mixtures indicated in the following table are in com- 
mon use, and the amount of material required to make a 
cubic yard of concrete in each case is also given. 

A rich mixture is used for beams, columns, and water-tight 
constructions. 



412 AGRICULTURAL ENGINEERING 

Material for one yard of concrete of different proportions. 



Mixture 


Proportions 


Cement, bbls. 


Sand, bbls. 


Gravel, bbls. 


Rich 


1:2:4 

1:2^:5 

1:3:6 

1:4:8 


1.57 
1.29 
1.10 

.85 


3.14 
3.23 
3.30 
3.40 


6.28 


Medium 

Ordinary 

Lean 


6.45 
6.60 
6.80 







Additional data: 1 bbl. of Portland cement weighs 376 lbs.; a 
sack, 94 lbs. A barrel contains 3.5 cu. ft. between heads. Concrete 
weighs about 150 lbs. per cu. ft. 

A medium mixture is used for thin foundation walls and 
for floors and sidewalks. 

An ordinary mixture is used for heavy walls which ar 
not subject to heavy strains. 

A lean mixture is used for heavy work where the material 
is subjected to only compressive stresses. 

Reinforcement. Concrete is a very good material to 
carry compressive stresses. Concrete and steel have very 

nearly the same coefficient of ex- 
pansion for changes in tempera- 
ture. This makes possible the use 
Fig. 262. sketch showing of a combination of j these mate- 

the proper location of steel in 

a concrete slab to resist tensile rials to the very best advantage 

stresses due to bending. . , .. .. . _, 

m building construction. the 
steel is placed in position to resist tensile stresses to the 
best advantage, and the concrete is poured around it. 
When used economically the cross-sectional area of the steel 
is equal to 34 to 1 per cent of the cross-sectional area of the 
beams. The steel is usually placed from % to 1 inch be- 
neath the surface of the concrete, in order to be thor- 
oughly protected from corrosion. 



Cj"->c^e£e Se 






1 



_^_ 



FARM STRUCTURES 413 

QUESTIONS 

1. Upon what three factors does the strength of a beam depend? 

2. Define maximum bending moment. 

3. What is the maximum bending moment for a beam 120 inches 
long and loaded at the center with 1000 pounds? 

4. Define modulus of section. 

5. What is the modulus of section for a 2x6? 

6. Define modulus of rupture. 

7. What is the modulus of rupture for white pine? Oak? Cast 
iron? 

8. Give the general formula for beams. . 

9. What load will a 2x6 white pine beam carry if the beam be 10 
feet long and the load be concentrated at the center? If the load hi 
uniformly distributed? 

10. Give the principal characteristics of the following building 
materials: stone, brick, lime, Portland cement, sand, concrete. 

11. Explain rich, medium, ordinary, and lean mixtures, and the 
use of each. 

12. Explain the principles involved in the reinforcing of concrete. 



CHAPTER LXV 
HOG HOUSES 

Essentials. The essentials of a good hog house are 
warmth in winter, coolness in summer, dryness, good ventila- 
tion, and adequate light. In addition it should be so arranged 
and located as to be convenient not only for caring for the 
animals but also for securing pasturage. A building which 
thoroughly protects the hogs from the wind and moisture is 
considered warm enough for all but the colder climates. Far- 
rowing houses must, of course, be made warm. 

Location. Drainage is highly important, and a well- 
drained location should always be selected. If the soil is of 
a porous or gravelly nature, it will make a more desirable site. 

Types of Hog Houses. There are two general types of 
hog houses in common use. The first type is the individual 
or colony hog house, or cot, as it is sometimes called, which is 
usually made portable and of sufficient size to accommodate 
one sow at farrowing time or one litter of pigs as they grow to 
maturity. 

The second type is the large or concentrated hog house, 
sometimes called the combined hog house, or piggery, and pro- 
vides several pens under one roof. This type of building is 
of more elaborate construction, and in many instances special 
care is used in the construction to secure a warm building for 
farrowing early litters. 

Advantages of the Colony House. There is much differ- 
ence of opinion, even among practical hog raisers and breed- 
ers, in regard to the relative merits of the two types of hog 



FARM STRUCTURES 415 

houses which have been described. The advantages of the 
individual or colony house may be summarized as follows : 

1. Each sow is free from disturbance at farrowing time. 

2. Each litter is reared by itself, and too many pigs are 
not placed in a common lot. 

3. The house may be placed at the opposite end of the 
lot from the feed trough, thus requiring the hogs to exercise. 

4. There is less danger of spreading disease, owing to the 
fact that each family is quite effectively isolated. 

5. If the location of the house becomes unsanitary, it 
may be moved. 

Advantages of the Large Hog House. The following 
advantages may be claimed for the large or concentrated 
hog house. 

1. This type is almost essential for early litters in north- 
ern climates. It is possible to construct a warmer building to 
begin with, and, if necessary, artificial heat may be provided 
by means of a stove or heating plant. 

2. It saves time in handling and feeding the pigs. In 
other words, less time is lost going from pen to pen. The 
distribution of feed and water becomes a big task where there 
are many pens to look after and where they are located at 
some distance from one another. 

3. The concentrated house saves fencing. 

4. The large house is generally of more durable con- 
struction and of better appearance, adding thereby to the 
value of the farm. 

5. It permits of larger pastures, which are more con- 
venient to renew or cultivate when rotated with other crops. 

Both types of houses are successfully used by practical 
men, and the type to be chosen must depend upon local condi- 
tions and individual tastes. 



416 



AGRICULTURAL ENGINEERING 



Dimensions. A farrowing pen should contain from 40 
to 140 square feet of floor. A common size is 8 by 10 feet. 
Stock hogs should have 6 to 12 square feet of floor, varying 
with their age. A farrowing pen usually has an outside pen, 
also, having an area of from 128 to 160 square feet or more. 




&- 0"- 



Front elevation of the "A" type of colony or portable 
hog house. (After Wisconsin Exp. Sta.) 



The cubic feet of air space per hog is not taken into consider- 
ation. Portable or individual hog houses are usually 6 by 8 
feet or 8 by 8 feet. 

When ventilating flues are provided, about 8 square inches 
of cross section should be provided for each grown animal. 



FARM STRUCTURES 



417 



THE INDIVIDUAL HOG HOUSE 

Construction. The individual hog house is constructed 
in a variety of shapes, of which the more general are the 
A-shaped house and the shed- and the gable-roofed houses. 
There does not seem to be a great difference in the merits of 
one shape over the other. 

The A-shaped house has the walls and roof combined. It 
is usually made of 1x12 boards, with the cracks covered with 
battens. The door should be about 2 feet wide and 2 feet 6 
inches high. A small window is usually located at each end 
of the house. A small ventilator in the ridge of the roof is 
desirable. It is recommended that the door be covered with 
burlap to prevent drafts in cold weather. Some breeders 



— H 



>r-\ 



z=z\==: 



i i 

r-6'-l 



% 



"=! 



;rr— j^&- 






-8-0' 



Fig. 264. Side elevation of the house shown in Fig. 263. 



418 



AGRICULTURAL ENGINEERING 



gbcfof/i/S' 
g&rn Boards 



prefer a cloth covering for the windows in place of window 
glass. 

This type of house is generally built on skids or runners, 
which facilitate its moving from one location to another. 
These runners may best be made of 4 x 6 pieces, although 
2x6 pieces are quite often used. Reinforced concrete skids 
have been used successfully for portable houses and have the 
advantage of being free from decay. 

Shed-roof House. The shed-roof house takes more 
material than any other shape, and is not generally made. 
The floor, sides, ends, and roof may be so made as to be taken 
apart for moving. Such construction might be an advantage 

where the house is to be 
moved a long distance; 
otherwise the use of skids 
would be far more conven- 
ient. 

Gable-roof House. The 
gable-roof portable house 
has many advantages, the 
principal one being the 
convenience of having cer- 
tain sections of the roof 
arranged for opening during mild weather and allowing the 
direct sunlight to enter. This can be done more effectually 
when the house is located east and west and a section of the 
south half of the roof is made to open. One or both of the 
sides may also be placed on hinges to open during warm 
weather. 

This house is built on skids, and should be provided with 
the window and burlap curtain like the A type of house. 




Fig. 265. 



Eno Vt&w 



End elevation of 
colony hog house. 



FARM STRUCTURES 



419 



THE LARGE OR CONCENTRATED HOG HOUSE 

Large hog houses, as distinguished from the colony house, 
vary largely in the arrangement of the windows, or the natural 
lighting. The value of direct sunlight in the hog house is 
generally appreciated. 

Construction. Houses are usually located so as to extend 
east and west, and when so located should have the half- 
monitor or saw-tooth type of roof. The windows of this type 
are so arranged that those in the lower row permit the sun 
to shine into the first row of pens, and the upper row into 
the row of pens on the north side of the building. Hog 




Fig. 266. A floor plan of a large hog house. 



houses built to extend north and south usually have gable 
roofs, and a row of windows on either side. 

There is much difference of opinion in regard to the rela- 
tive merits of these two types of roofs. It is safe to say that 
either will prove entirely satisfactory when properly con- 
structed. 

The half-monitor roof requires more material than the 
gable-roof house. The upper part of the building is solely 
for the purpose of letting sunlight into the black pens. Such 
construction prevents the proper control of the temperature, 
as there is a large pocket above into which the warm air may 
lodge. The back rows of pens with this construction is 
shaded more or less throughout the entire year. The open- 



420 



AGRICULTURAL ENGINEERING 



ings on the north side of the building are criticised severely by 
some as being highly undesirable. On the other hand, the 
principal redeeming feature of this type of house is that the 
windows may be placed so as to do the most good. 

The half-monitor roof is usually built about 24 or 30 feet 
wide. It is desirable that the alley-way be 8 feet wide, to 
permit a team and wagon to be driven through the house when 
desired. The pens at either side may be from 8 to 12 feet 




Fig-. 267. A cross section of a hog house with half monitor roof. This 
is located so as to extend east and west. 

deep and about 8 feet wide. Fig. 267 shows a cross section 
of a house with the windows well arranged. 

A cross sectionof a gable-roof hog house is shown in Fig. 278. 
The sunlight enters the east windows early in the morning 
and travels across the floor, as the sun rises higher, until nearly 
noon, when it is excluded until it begins to shine in through 
the west windows. It is to be noticed that this type of house 
uses less material than the first, owing to the fact that there 
is not so much space in the upper part of the house. 



FARM STRUCTURES 



421 



The lighting of this type of house is sometimes augmented 
by building a monitor above the alley-way and supplying two 
additional rows of windows. This construction adds con- 




Fig. 268. Cross section of a hog house with gable roof. 



siderably to the cost. A type of house which is being used 
and developed in Iowa is one with a skylight running through- 
out the entire length of the building. This system of lighting 



Green- house 
Vyindow. 




Fig. 269. Cross section of a hog house with a sky-light in the roof. 
Direct sunlight strikes all parts of the floor during the day. 



422 ■ AGRICULTURAL ENGINEERING 

is obviously the best of all, as a solid band of sunlight must 
pass across the building every day, striking every part. With 
windows, only spots of direct sunlight enter the building, and 
even when great care is used in the design of the building this 
light strikes but a relatively small proportion of the total 
floor space. With this new type, the only portion of the entire 
building not covered is the south end, and windows may be 
provided to light this portion thoroughly. 

The objection has been raised that this skylight would be 
damaged by hail. An investigation shows that the loss of 
greenhouse glass is not great, and it would be possible to pro- 
tect the glass with a wire net if thought best. This construc- 
tion is the cheapest of all, as the building may be built quite 
low and the cost of the sash for the skylight is not much 
greater than the cost of regular roofing materials. In some 
instances it may be necessary to arrange a shade under the 
skylight if the house is to be used much during the summer 
months. 

The Foundation. The foundation of a hog house need 
not be heavy. A 6-inch concrete wall or an 8-inch brick 
wall will be found adequate if placed on a 12-inch footing. 
The foundation should extend below the. frost line if the 
building is to retain its shape well. 

Floors. Earth, plank, and concrete are used for the hog 
house floors. Earth is objectionable on account of the diffi- 
culty of cleaning the house thoroughly. Plank is not desir- 
able, for it furnishes a harbor for rats. Concrete makes a 
very desirable floor but has the objection of being cold. 
Many practical breeders find that this objection has little 
weight if the floor be placed upon thoroughly drained soil and 
the hogs are provided with a liberal amount of bedding. A 
portion of the floor may be covered with boards. The usual 
sidewalk construction should be used for concrete floors. 



FARM STRUCTURES 



423 




Walls. Drop siding upon 2x4 studding two feet on 
center is usually used for the walls of the hog house. In 
cold climates this construction with a layer of sheeting and 
building paper between 
should be used. Ship-lap 
makes a very desirable 
covering for the inside of 
the house. 

Clay blocks make a 
very good wall, and are 
cheap. No doubt they 

Will COme into more gen- Fi =- 27 °- A , sable-roof hog house made 

° of concrete blocks. 

eral use. Concrete walls 

are very desirable, and, where gravel and sand can be secured 
cheaply, are much to be preferred over less durable construc- 
tion. 

The Roof. The usual method of constructing the roof is 
to lay shingles or prepared roofing over sheathing in the usual 
way. When nearly flat roofs are used, as with the half- 
monitor types, prepared roofing is preferable. 

Partitions. Partitions should be 3j^ feet high. Solid 
partitions are advised by a few, as they keep the hogs separate ; 
but open partitions intercept less light and when sows see 
one another and the attendant they give little trouble from 
interference or fright. Doors and troughs should be arranged 
for convenience. The front partitions may be arranged to 
.swing over the troughs for handy cleaning and feeding. 
Metal partitions, made of a metal frame with woven wire 
fencing across, have not generally proven satisfactory. As 
usually made they are not stiff enough, and generally give 
trouble from bending out of shape. If made heavy, metal 
partitions are quite expensive. 



424 AGRICULTURAL ENGINEERING 

QUESTIONS 

1. What are the essentials of a good hog house? 

2. Where should a hog house be located? 

3. Describe two types of hog houses. 

4. Give the principal advantages and disadvantages of each type. 

5. What is a good size of farrowing pen? 

6. Describe the following types of individual hog houses: the 
A-shaped, the shed-roof house, and the gable-roof house. 

7. Describe the arrangement of windows in the half-monitor and 
gable-roof hog houses. 

8. Explain how a skylight may be used effectively to light a 
hog house. 

9. Describe the construction of the foundation, the floor, the walls, 
and the roof of a large hog house. 

10. Discuss the construction and arrangement of partitions in a 
large hog house. 



CHAPTER LXVI 
POULTRY HOUSES 

Location. Poultry houses should be located on well- 
drained, porous soil. Surface drainage is important, and, if 
necessary, it is always possible to modify the surface by 
grading. A gentle slope to the south or the southeast is best. 
A good windbreak is necessary, but there should be sufficient 
air drainage. 

Poultry houses should not be made a part of, or located 
near, other farm buildings which may furnish a harbor for 
vermin that will prey upon the young fowls. Poultry houses 
may be quite close to the dwelling house, as in many instances 
the women of the farm have the care of the poultry. 

Dimensions. Modern poultry houses are usually built 
on the unit system, that is, in sections for each flock of 25 to 
100 birds. There has been much development of late years 
in regard to the amount of air and sunlight admitted to the 
poultry house; in fact, some houses are now built with one 
side entirely open to the weather. The poultry house is sel- 
dom built wider than 12 feet, although wider buildings may 
be more economical as far as space obtained for material used 
in construction is concerned. The unit or section is usually 
16 feet long. 

Space for Each Fowl. The space for each fowl is usually 
based on the area of floor surface rather than upon the cubical 
space. Four to six square feet is usually allowed for each 
fowl. The breed of the fowl, the range or size of the lot, the 
climate, and the size of the house are factors to be taken into 
account in deciding upon the amount of space for each fowl. 



426 



AGRICULTURAL ENGINEERING 



Small birds require less space, and the wider the range the 
less the space required. More space is needed if close con- 
finement is necessary on account of the weather; and if the 
flock is large each individual bird will have more freedom, 



m 



>f 



b * 



m 



t—2-o'Cerien » 




Plan 

Fig. 271. Plan of an A-shaped colony poultry house. (la. Exp. 
Sta. Bui. 132.) 

requiring less space per fowl. In some instances the floor 
space per fowl has been reduced to 2 x /2 square feet. 

It is a good rule to allow at least one cubic foot for each 
pound of live weight, or from 5 to 20 cubic feet per fowl. If 
enough height be provided for convenience in caring for the 
fowls, there will be plenty of volume. 

The Foundation. Poultry houses are of light con- 
struction and do not need elaborate or expensive founda- 
tions. Colony houses are built upon skids. It is well that 
the foundation of the nonportable houses be so constructed 
as to exclude rats. If clay blocks or other masonry con- 
struction be used, the foundation should extend below the 
frost line, to overcome the damage which might be done by 



FARM STRUCTURES 



427 




Front Elevation 



Front elevation of the house 
shown in Fig. 270. 



the heaving action of the frost. Masonry foundations are 
to be preferred on account of their greater durability. 

Walls. Any wall construction will be satisfactory so 
long as it will prevent 
drafts, retain the heat, 
prevent the condensation 
of moisture, and furnish a 
smooth surface which may 
be entirely freed from mites 
and other vermin. The 
following wall construc- 
tions are generally used : 

1. Walls made of a 
single thickness of boards, 
matched or battened. 
Usually this construction 
is too cold for anything except southern climates. Building 
paper may be used on the inside of the boards to make the 
walls air-tight. 

2. Double wall, same as above, except ceiled on the 
inside. For general use this construction is fairly warm but 
gives trouble from condensation of moisture. 

3. Same wall as No. 2, but the space between the outside 
and inside boards is filled with hay or other insulating mate- 
rial. This is a very warm wall and gives little trouble from 
condensation. 

4. Same as No. 3, except the inside sheeting is replaced 
with lath and hard plaster. The latter gives a finish which 
may be thoroughly disinfected when desired. 

5. Masonry walls of concrete or clay building blocks. 
Concrete makes a good wall for a poultry house if made 
double. 



428 



AGRICULTURAL ENGINEERING 



6. Small houses may be covered with prepared roofing 
laid over plain or matched lumber. Such construction is 
warm and air-tight. 

Floors. The cheapest floor for the poultry house is the 
earth floor, but it is likely to give trouble from dampness, 
and is dusty and difficult to keep clean. Clay should be used 
for the floor in preference to a loam soil. The earth surface 
may be removed occasionally, or the entire floor may be 




Perspective 
°r nests 



Fig. 273. Detail of nests for house shown in Fig 270. 

replaced with new earth. Another objection to the earth 
floor is that it is not vermin-proof. 

Board floors are quite expensive, not very desirable, and, 
to be warm, should be made double, with a layer of tar paper 
between the two layers of boards. Board floors are likely 
to form a harbor for rats. 

Cement floors are the most durable, the easiest to clean 
and disinfect, and are quite reasonable in cost. The objec- 



FARM STRUCTURES 



429 



tions to the cement floor are that they are very hard, cold, 
and quite likely to be damp. A liberal use of litter on the 
floor will overcome the first two objections. If placed on Well- 




Note.— 

Roosts ond Droppinq board 
be removed separately 



F%^ 



Rodsts »» Drdpfinb Board 

Fig. 274. Detail of roosts and dropping board. 

drained soil or on a porous foundation of cinders or gravel the 
floors ought not to give any trouble from dampness. Light 
sidewalk construction makes a satisfactory floor. 

Roofs. The roofs of poultry houses are made in various 
shapes, the principal object sought with any style is to secure 
plenty of windows with the least material. Although gable 




Perspective 



Framing 



Fig. 275. The frame of the house of Figs. 271 to 274. 



430 



AGRICULTURAL ENGINEERING 



roofs and half-monitor roofs are used to quite an extent, the 
shed-roof house, extending east and west with the slope of the 
roof to the north, is the prevailing type in this country. 
This type of roof gives an abundance of room for windows 
or muslin curtains. Where the house is made portable and 
is to be moved among trees, as would be the case in an 




Fig. 2iG. A photograph of the house shown in Figs. 271 and 



orchard, the combination roof may be used to advantage. 
This roof is like the shed roof, except a small portion is made 
to slope to the front, reducing the height of the building. 

Shingles may be used for the roof if the pitch is one-third 
or greater, and building paper is used under the shingles to 
make the roof air-tight. 



FARM STRUCTURES 



431 



Prepared roofing is very satisfactory for the roofs of poul- 
try houses, as it is air-tight, and when a good quality is used 
its durability will compare favorably with shingles. 



m 



1= 



! HZfl g - 



e: 



4' .Studs 2-o - Centers 



¥ 



5 



2*4 Roo^s 



Horse ^«|j 



^ 



Roosts and Center Horse can be 
removed separately 'from th<> rVo D - 
pna board 



(NlOTE. 

End doors may be omitted 
if only one section of +he 
house is built. 




Plan 

Fig. 277. Plan of a farm poultry house with shed roof. (la. Exp. 
Sta. Bui. 132.) 

Windows. It is recommended by good authority that 
there should be at least 1 square foot of window glass well 
placed for each 16 square feet of floor space. The tendency 
in the development of poultry-house construction has been 
toward large glass or curtain fronts facing the south to let in 
the warmth during the day. The muslin curtains are 
mounted on frames which permit them to be opened and 
closed with ease. The openings for the curtains are covered 
with wire cloth or netting. 



432 



AGRICULTURAL ENGINEERING 



Doors. The doors for poultry houses are found to be 
the most convenient when hung on double-acting hinges. 
Doors so hung can be pushed open even if the hands are filled. 

Partitions. The partitions in continuous houses may be 
made of boards or plaster. It is quite a common oractice 
to use poultry netting for the upper part, but the lower part 
should always be made solid. 

Ventilation. Although flues or the King system (see 
chapter on ventilation) could be used to ventilate poultry 




Front Elevation 



-io'i 



-j^-4'Tile 



Fig. 278. Front elevation accompanying Fig. 277. 



houses, ventilation is generally secured by means of cloth 
fronts. For other farm buildings this means of ventilation 
has not proven satisfactory, but has been successful with 
poultry houses. 

Types. Poultry houses are constructed after two plans: 
(1) the colony system, consisting of isolated houses usually 
made portable for each flock; and (2) the continuous system, 
consisting of several adjoining units with pens for each. 



FARM STRUCTURES 



433 



Development, however, has brought out the following three 
popular types of houses: 

1. The scratching-shed house is built in sections con- 
taining two rooms, one for feeding and scratching and the 
other for roosting and laying. 

2. The curtain-front house, commonly called the Maine 
Station House. In this construction the roosting and laying 
room is in the rear of the scratching pen. 

3. The fresh air or Tolman house. In this house the 
front and parts of the sides are open. No more protection 




Fig. 279. Details of the nests of the house shown in Figs. 277, 278. 



is secured for the fowl at night than during the day. This is 
essentially a colony house, but may also be constructed on the 
continuous plan. 

Nests. The size of the nests will depend on the size and 
breed of the birds, but should be 12x12 inches and 5 inches 



434 



AGRICULTURAL ENGINEERING 



deep for Leghorns or small fowls, and 14x14x8 inches for 
Cochins or Brahmas. 

Special Features. The poultry house should be wind 
proof and free from drafts. A curtain placed in front of the 
roosts will keep fowls warm in severe weather. 

The nests should be dark, for hens lay better in such nests, 
and the egg-eating habit is prevented. 

Due protection against mites and lice should be provided 
by making the house smooth and free from cracks on the 
inside. 

The nests, roosts, and droppings board should be remov- 
able for cleaning or spraying. 

The roosts should be about 234 feet from the floors, with 
all bars at the same height, as ladder roosts cause the birds to 




Perspective 

OF 

Roosts 



Fig. 2S0. Details of roosts of the house shown in Figs. 277 to 279. 



crowd to the top bar. The roosts are best when about 2 
inches wide and only the corners rounded, and rigid enough 
to prevent one bird from disturbing others on the same bar. 
The bars ought to be placed 12 to 14 inches apart and 8 to 12 
inches allowed for each bird. 



FARM STRUCTURES 435 

QUESTIONS 

1. Where should the poultry house be located? 

2. How much space should be allowed for each fowl? 

3. Describe suitable foundations and walls for poultry houses. 

4. Discuss the construction of the poultry house floor. 

5. What are the common types of roofs for poultry houses? 

6. What materials may be used to good advantage in the con- 
struction of the roof? 

7. Discuss the management of windows for poultry houses. 

8. What are the curtain fronts for poultry houses? 

9. Discuss the arrangement and construction of doors and parti- 
tions. 

10. What is the usual provision for ventilation in the poultry house? 

11. Describe the usual types of poultry houses. 

12. What should be the size of the nests? 

13. Discuss some of the special features of poultry-house construc- 
tion. 



CHAPTER LXVII 
DAIRY BARNS 

Essentials. The essentials of a good dairy barn may be 
enumerated as follows: 

1. Warmth. Dairy cows cannot be expected to produce 
well unless comfortably housed. Cows protected from cold 
require less feed. 

2. Sanitation. Since dairy products are used for human 
food and since there is nothing that is so easily contaminated 
with filth and disease as milk, the sanitation of dairy barns is 
perhaps the most important factor in their construction. 

3. Ventilation. In order that cows shall produce well 
and remain healthy, they must be provided with plenty of 
fresh air. 

4. Light. As explained in another chapter, adequate 
natural lighting is necessary to cope with disease. 

5. Dryness. Barns must be dry; damp barns breed 
disease. Ample drainage must be provided. 

6. Convenience in handling stock and feed must be con- 
sidered. 

7. Box Stalls. The barn must have provision for box 
stalls, also pens for young stock and the bull, unless other 
provision is made. 

8. Storage room of sufficient capacity to suit conditions 
must be provided for feed. 

Types of Barns. Dairy barns may be classified according 
to the method of handling the cows and also according 
to the height of the building. The open feed room type of 
dairy barn is arranged to let the cows run loose, and has but 



FARM STRUCTURES 



437 



a few stalls for use in milking. This style is well adapted to 
certified milk production, as each cow may be groomed before 
milking. An objection to this type of barn is that the cows 
cannot be fed individually. It saves time in feeding, how- 
ever, and the cost of construction is low. 

The barn with stalls is the more common type. In com- 
parison with the other system it may be said to be economical 
of room and that it enables each cow to be fed her proper 
ration. The cows are under better control, and it is easier to 
save and handle the litter. 

Shed or single-story construction has the advantage of 
being well lighted and easily kept clean, but is not economical 




Fig. 281. Floor plan of a modern dairy barn. 

in construction. This type usually has a monitor roof, with 
a row of windows on each side. A loft or storage floor sup- 
plies economical space and enables the barn to be kept warm 
more easily. In this case all light must come from side win- 
dows. 

The Foundation. The foundation for a dairy barn should 
extend below frost and should be on firm soil. The width of 
footing may vary from 12 to 16 inches. An 8-inch founda- 
tion wall of concrete or hard-burned brick is sufficiently 
strong; a wall of rubble work should be wider. Sills should 
be 12 to 15 inches above the floor. 



438 AGRICULTURAL ENGINEERING 

Walls. It is essential to have a wall dry and warm, and 
smooth on the inside. Drop siding is often used on the out- 
side of the studding and smooth ceiling on the inside. In 
mild climates a single wall is satisfactory, but in northern 
climates a double wall must be used. A cement-plastered 
wall on the inside is very suitable from a sanitary standpoint. 
In extreme cold localities the walls may be stuffed with hay 
or shavings. A monolithic, or solid, concrete wall is damp, 
but a hollow wall is very satisfactory. These walls are made 
with about a 4-inch air space between a 5-inch outer wall and 
a 3-inch inner wall, reinforced and tied together with iron or 
steel headers or ties. 

Windows. Windows should be placed to give maximum 
light; about 1 square foot of glass to 20 to 25 feet of floor 
space is adequate. 

Space Required. A common rule is to allow 1 cubic foot 
of space for each pound of live weight housed. For the av- 
erage dairy cow 500 to 700 cubic feet is sufficient when there 
is proper ventilation. The stalls should be from 36 to 42 
inches wide, for average conditions. The ceiling is usually 
8 feet in the clear. 

Floors. Cement floors are the most satisfactory, but 
are condemned because they are cold. But if dry and pro- 
vided with sufficient bedding, they should be satisfactory in 
every way. They are by far the most sanitary. Board floors 
may be used but are not durable and are more difficult to 
clean. No woodwork should be imbedded in cement floors. 

Cork and wood blocks are used to some extent but have 
not passed beyond the experimental stage. 

The Roof. Shingles or a high grade of prepared roofing 
may be used. 

Size of Gutter. The gutter is usually 14 or 16 inches 
wide and 4 to 10 inches deep. The bottom may be level, 



FARM STRUCTURES 



439 



crosswise, or sloping to one side. The latter is objectionable, 
as cows sometimes slip in a gutter with a sloping bottom. 
The gutter should have a slope lengthwise of 1/16 to 1/10 inch 
per foot for drainage. 

Facing of Cows. Opinions differ as to the advantages of 
facing cows in or out when two rows of stalls are used. Stalls 
that face in are convenient in feeding, and the cows do not 
face the light, which is said to be injurious to their eyes. Ven- 
tilation may also be more effective. The opposite system 




Fig. 2S2. Interior of a modern dairy barn. 

gives advantages in removing the litter and in milking and 
handling the cows. 

Mangers. The mangers for dairy barns are made of 
plank, concrete, or sheet steel. Concrete mangers are more 
sanitary and durable than wooden mangers, but are more 
expensive. They should be made continuous, with a drain 
at one end for cleaning. The back side of the manger must 
be from 4 to 6 inches high, enabling the cows to lie down. 
Mangers are usually about 3 feet in width over all. Box 
mangers should be made removable, to facilitate cleaning. 



440 



AGRICULTURAL ENGINEERING 



Patented mangers may be purchased which rest on the floor, 
having no bottoms, and which may be raised out of the way 
for cleaning. 

Ventilation. (See Chapter LXXXIV on this subject.) 
Stalls. Stalls for dairy cattle vary in length from 4 to 
5 feet, and in width from 3 to 4 feet. The requirements of 
the different breeds in this respect vary widely. The length 
refers to the distance from the manger to the gutter. A 
stall 4 feet 6 inches long and 3 feet 6 inches wide is suitable 
for average conditions. 

Wooden stalls or partitions are being rapidly displaced 
by metal ones. The modern stall, as shown in Fig. 282, is 
made entirely of pipe or tubing, with bolted connections. 
The size of pipe or tubing generally used has an outside 
diameter of 1^ or 1% inches. 




Fig. 283. Cross section through stalls in a modern dairy barn. 



Cow Ties. One quite satisfactory method of securing 
cows in the stalls is by means of a strap around the neck 
snapped to a ring in a chain extending between the posts 
of the stall. This device permits of a reasonable amount 
of freedom for the cow. . 

The stanchion, however, is the device more generally 
used, and the later models of swinging stanchions leave little 
to be desired. The old-style fixed stanchions were too 
rigid, but the present forms are supported at the top and 
bottom by short lengths of chain, giving greater freedom of 
movement to the cow. 



FARM STRUCTURES 441 

QUESTIONS 

1. What are the essential features of a good type of dairy barn? 

2. Describe the various types of dairy barns with reference to 
methods of handling the dairy cows and the height of the building. 

3. Discuss the construction of the foundation for a dairy barn. 

4. In like manner discuss the construction of the walls and the 
roof. 

5. How determine the proper amount of window surface? 

6. Discuss the construction of the floor. 

7. How much space is required per cow? 

8. What should be the size of the gutter? 

9. Discuss the relative merits of having two rows of stalls face in 
or out. 

10. What should be the size of the manger? Discuss its construc- 
tion. 

11. What should be the dimensions of a stall for a dairy cow? 

12. Describe the construction of suitable stalls. 

13. Describe the chain cow tie. 

14. What advantages does the swinging stanchion offer as a cow tie? 

15. Discuss the construction of mangers for the dairy barn. 



CHAPTER LXVIII 



HORSE BARNS 

Some important features of horse-barn construction are: 
1. The location should be prominent, as it is one of the 
most used of farm buildings. 

2. Good surface and underdrainage are necessary. 

3. The barn should be well lighted. 

4. Provision for sufficient hay and feed must be con- 
sidered. 

5. Vehicle storage is often needed. 



-6V 



' *— S — ika 1 *-?-*-^^ 4-*-S^— f^-taii 




Fig. 2 84. Floor plan of a general farm barn. 

Space. Each horse will require from 700 to 1000 cubic 
feet of air space. The barn must be 20 feet wide for a single 
row of stalls and 30 feet for a double row. 

The foundation should be of stone, concrete, or hard- 
burned brick, and should extend below frost with sufficient 
width of footing. Piers of stone and concrete are often used. 

Ceiling. The ceiling of horse barns should be at least 8 
feet in the clear. 



FARM STRUCTURES 



443 



Walls. The walls of horse barns need not be as warm 
as those for dairy barns. The single wall is often considered 
sufficient except in the most severe climates. 

Floors. The floor may be of cement or plank, but clay 
is often preferred for the front half of the stall, at least. A 
shallow, covered gutter 2 inches deep is a good thing when 
proper drainage can be provided. 

Facing. The horses may be faced in or out, and the 
same conditions apply that were mentioned under dairy barns. 

The feed alley should be at least 3 feet wide, and a width 
of 4 feet is desirable. A drive-way should be 8 feet wide 
for a wagon or manure 
spreader, and 12 feet wide 
for a hayrack. 

Stalls. Horse stalls are 
usually made of two-inch 
lumber. Pipe partitions 
have been used to a very 
limited extent. The ac- 
companying sketch shows 
a very satisfactory type 
cf stall where simplicity 
of construction is desired. 
Single stalls for horses vary 
much in width, all the way from 3 feet 8 inches to 6 feet. 
Five feet is considered a good width. Double stalls are 
usually made 8 feet wide. A good length of stall is 9 feet 
6 inches, measured from the front of the manger to the back 
of the partition. Box stalls vary from 8x10 feet for a small 
stall to 10x12 feet for one of liberal size. Stall partitions 
should be about 6 feet high. 

Mangers, etc. Mangers are usually 2 feet wide and 3 
feet 6 inches high. The floor of the manger should be about 
15 inches above the floor. 




A general farm barn with 
gambrel roof. 



444 



AGRICULTURAL ENGINEERING 



Water troughs should be provided at a convenient point. 

A harness room is essential in order to protect the leather 
from stable fumes. 

Hay carriers should be so installed as to enable the mow 
to be filled readily. 

Ventilation. (See Chapter LXXXIV.) 




6 




&4- 

Oection thru £x-6 



Fig-. 286. Detail of construction of a horse stall. 



QUESTIONS 

1. What are some desirable features in the horse barn? 

2. How much space should be provided for each horse? 

3. Discuss the construction of the horse barn with reference to 
foundation, ceiling, walls, and floor. 

4. How wide should feed alleys be? 

5. Discuss the construction of horse stalls. 



CHAPTER LXIX 
BARN FRAMING 

Roofs. Several types of roofs are used in barn construc- 
tion. The hip roof, which slopes from the four sides of the 
barn to a point, is sometimes used for small barns. The 
shed roof, which slopes only one way, is used for narrow barns. 
The gable roof slopes in two directions and has gables, from 
which it derives its name. Gable roofs are quite generally 
used for barns. The curb or gambrel roof is much like the 
gable roof, except each side of the roof has two pitches. 
This type of roof is quite generally used for barns, and, in 
addition to being quite rigid when properly constructed, it 
adds to the capacity of the haymow. 

The Braced or Full Frame. In this type of frame heavy 
timbers are used, which are mortised and pinned together. 
Many barn frames have been made after this style, but the 
cost of the lumber and the advantages of the plank frame 
have caused an almost complete discontinuance of this style 
of frame. When now used it is a modification of the old 
form. 

The Plank Frame with Purlines. In this type of barn no 
attempt is made to keep the haymow free from framework, 
and the long rafters are supported upon the purlines resting 
upon posts throughout the frame. It is possible to keep the 
mow free from framework directly under the hay carrier 
track, and when so constructed it should not be inconvenient. 
This type of a frame is not generally popular, but there can be 
no serious objection to having the posts support the rafters 
when they are properly placed. 



446 



AGRICULTURAL ENGINEERING 




A model Wing joist barn frame. 




Pig. 2SS. A model Shawver barn frame. 



FARM STRUCTURES 



447 



The Wing Joist Frame. The Wing joist frame is made 
entirely of 2-inch lumber. The frame consists of bents or 
sections placed at intervals of 10 to 16 feet. The wall posts 
usually have five pieces of 2-inch lumber below the mow, two 
of which are continuous, and extend to the plate on which the 
rafters rest. Girders running across the barn from post to 
post are usually made of three pieces of 2-inch lumber. A 




8'*IO~Column_ ', 
from 5-Z''8s 



Fig. 289. A sketch of the Wing joist barn frame. 



diagonal brace is placed from the top of the post supporting 
the plate to an inside post to care for the thrust of the rafters. 
Vertical siding is usually nailed to girts on the outside of 
the posts. Plates for the rafters are made of two pieces of 2- 
inch lumber in the form of a box. Iron rods are sometimes 
used to brace the plates, but wooden braces are preferable, 



448 



AGRICULTURAL ENGINEERING 



owing to the fact that they are not only strong in tension 
but are stiff and make a more rigid structure. 

A curb roof is used, and the rafters, which are usually 2x6's 
are strengthened at the curb by braces of inch boards or 2- 
inch pieces cut to fit underneath. The rafters are usually 
placed two feet apart on the larger barns of this construction, 




i 



11 W'rfSrW "^ 



5-2-rs- 



34 -O' 



Fig. 290. A sketch of the Shawver barn frame. 

and should have diagonal braces to make the frame more 
rigid. The Wing joist frame is not adapted to barns over 
40 feet wide. 

The Shawver Barn Frame. The Shawver barn frame, 
as now constructed, consists of bents made up of 2-inch lum- 
ber and placed 8 to 16 feet apart, on which the wall and rafter 



FARM STRUCTURES 



449 



coverings are placed. The Shawver frame is quite thor- 
oughly braced in every way, as is shown by the accompanying- 
drawing. It is one of the standard forms of barn frames. 

Steel Frames. Steel frames are now manufactured for 
barns to a limited extent. The frame is made entirely of 
steel in the shop ready to set up. They are generally more 
expensive than the wooden frames. 

Round Barns. In some localities the round barn is very 
popular. In general, it has two serious objections: (1) It 
is quite difficult to light a large round barn efficiently, and 
(2) it is difficult to ar- 
range the barn so as to 
prevent a considerable 
waste of space. A lar- 
ger space can be enclosed, 
however, within the wall 
of the round barn than 
in any other type using 
the same amount of ma- 
terial. Generally the 
frame for the round barn 
consists of studding, 
spaced about two feet 
apart, on which wooden 
hoops of inch lumber 
bent to the circle are 
nailed. The roof is conical in form and is very rigid. 



77 \^ 

I H 



Fig. 291. 



A sketch of a barn frame with 
posts and purlins. 



Most 



round barns have a double pitch to the roof, with the rafter 
cuts as for the Wing joist frame. 



QUESTIONS 

1. Discuss the merits of shed, gable, and gambrel roofs for barns. 

2. Describe the braced or full frame for a barn. 



450 AGRICULTURAL ENGINEERING 

3. Describe the construction of a plank-frame barn with purlines. 

4. Describe the construction of the Wing joist frame. 

5. Describe the construction of the Shawver plank frame. 

6. What are the principal advantages and disadvantages of a steel 
barn frame? 

7. What are the objections to a round barn, and its principal 
advantages? 

8. Describe the usual method of framing a round barn. 



CHAPTER LXX 
THE FARMHOUSE 

The purposes of a farmhouse are: 

1. To be a home, a meeting place of the family. 

2. To afford protection. 

3. To house the various goods and treasures of the family. 

4. To provide a place for the administration of the farm. 

5. To adorn the landscape. 

In brief, the farmhouse should represent comfort, con- 
venience, and economy. 

Location. Consideration should be given to the follow- 
ing features in the location of the farmhouse. The health- 
fulness of the location should be given first consideration. 
The site should provide water and air drainage, and on this 
account a hillside slope offers many advantages. A well 
should be within reasonable distance, if a supply of good 
water is not supplied by other means. The barn should 
not be too far away. A suitable place for a table garden 
should be near. If located too far from the road, the house 
will be lonely; if too near, privacy will be lost. 

Designing the Farmhouse. Each house must be designed 
to fit particular conditions and requirements. Plenty of 
time should be used in preparing the plan. It is best to con- 
sult a practical builder or architect. The preliminary draw- 
ings should be drawn to scale in order that the planning may 
be carried on more intelligently. Arrangements should be 
made for possible improvements. 

The Foundation. The foundation should be made of 
goo d, durable masonry and should extend below frost for about 



452 AGRICULTURAL ENGINEERING 

3^2 feet, under most conditions. A brick wall 8 inches thick 
is sufficient. Stone walls are usually made 12 to 18 inches 
thick, according to the difficulty of laying a wall of less thick- 
ness. A concrete wall 6 to 8 inches thick is satisfactory. 
A double wall is preferable because it is much drier. The 
footing of the wall should be 6 to 8 inches wider than the 
wall. 

The Cellar. The cellar wall should extend at least 2 feet 
above the ground line, to provide window space for adequate 
lighting. Great care should be taken to make the cellar 
wall as dry as possible. In some instances it is necessary 
to plaster the outside, making it air-tight, and to lay a drain 
tile line outside the footing. Often material can be saved 
by building the cellar under the entire house. Such con- 
struction is regarded as the most sanitary, if the cellar can 
be kept dry. 

If a furnace is to be installed, the ceiling should be suffi- 
ciently high to provide room for the installation of the warm 
air pipes. 

THE PLAN . 

The Dining Room. The dining room is often regarded 
as the center of the farmhouse, and is in most instances used 
as the living room. When so used it should be large enough 
to contain not only the dining table, but also a library table 
and a bookcase. The dining room should have plenty of 
light, and a southern or western exposure is preferable. 

The Kitchen. The kitchen of the farmhouse ought not 
to be too large, if it is not used as the laundry. Large 
kitchens are the cause of unnecessary work. It is best to 
arrange the kitchen with fixed cupboards and to provide a 
sink and a convenient location for the range. 



FARM STRUCTURES 



453 



The Pantry. Every modern house should have a pantry, 
which is most convenient when in connection with both the 
kitchen and the dining room. 

The Sleeping Rooms. The sleeping rooms may be as 
small as 10x10 feet, but 12x14 feet is preferable. All 
sleeping rooms should be provided with closets. 

The Staircase. The staircase should be wide and not 
too steep. Winding steps are to be avoided. 

The Bathroom. The bathroom may be as small as 6x8 
feet, but 8x10 feet is regarded as a good size. It is most 




Fig. 292. First and second floor plans of a farmhouse. 

convenient for the installation of plumbing when located 
over the kitchen. The bathroom should have an outside 
window for ventilation and light. 

The Washroom. Although not usually provided, the 
farmhouse should have a room where the men of the farm 



454 AGRICULTURAL ENGINEERING 

may hang their extra coats and stable clothes. This room 
should have lavatory facilities, enabling the men to wash 
before entering the dining room. 

The Laundry. Nothing is more useful in a well-designed 
farmhouse than a room equipped as a laundry. When 
adequate drainage can be secured, it is best located in the 
basement. 

QUESTIONS 

1. What are the purposes of a farmhouse? 

2. What are the requisites of a good location for a farmhouse? 

3. What course should be followed in designing a farmhouse? 

4. Discuss the construction of the foundation. 

5. How should the cellar of a farmhouse be constructed? 

6. Discuss the special features to be considered in the planning of 
the dining room. The kitchen. The pantry. The sleeping rooms. 
The bathroom. The washroom. The laundry room. 



CHAPTER LXXI 
CONSTRUCTING THE FARMHOUSE 

The Full Frame. The full frame corresponds to the full 
frame for barns, made of dimension stuff, mortised and pinned 
together, and in which the wall frames are raised as a unit. 
This framing began to be displaced by the balloon frame 
about 1850, and is now used only in a modified form. It 
resists fire better than the balloon frame, but may not be any 
more substantial. 

The Balloon Frame. The balloon frame is made of light 
timbers, usually 2 inches thick and of varying widths. The 
usual method of construction is to lay the sills, which may be 
either a box sill of two 2x8 timbers, or a 4x6 timber. The 
latter is halved in splicing at the angles and in the corners. 
In the case of the box sill, one piece is laid on the wall and 
the other on edge upon the first. The sills support the first- 
floor joists, and from them, also, the studs, generally 2x4's, 
are erected. The studs are made double at the corners and 
at each side of the openings for doors or windows. They are 
placed 16 or 12 inches o. c. (apart), the former being the usual 
spacing. The studs extend to a double plate of two 2x4 
scantlings. They may be extended by a second piece placed 
end to end and spliced with boards nailed on each side. The 
joists for the second floor are supported by a girt or ribbon of 
lx4-inch boards let into the studding. The studding at 
each corner should have a lx6-inch brace notched in, or a 
diagonal brace made from a 2x4 fitted between the studs . The 
rafters for the attic are supported by the top plate and the 
joists. A common practice is to use a box sill, lay the rough 



456 



AGRICULTURAL ENGINEERING 



flooring, and place the studding on a bottom plate nailed to 
the flooring. To support the studding well, the rough floor- 
ing should be laid diagonally ; otherwise all the studding on 
one side will be attached to one board. 

It is very difficult to prevent a one-and-a-half story 
house from sagging, due to the thrust of the rafters on the 
plate, which cannot be held together. 

Bridging. Bridging consists of diagonal strips, usually 
1x3 inches in cross section, nailed between the floor joists to 




Fig. 293. A concrete block house representing a good type for the farm. 



stiffen and strengthen them. Joists 8 to 16 feet long should 
be bridged once; those 18 to 24 feet long, twice. The floor 
should be leveled as the bridging is nailed fast. Two lOd 
nails should be used at each end of the bridging pieces. 

The studs should extend from sill to plate in interior walls 
the same as for outside walls, in order that shrinkage will 
be uniform. 



FARM STRUCTURES 457 

Sheathing. It is advisable to put sheathing on diago- 
nally, as it then strengthens the frame very much, and the 
extra cost of wasted material and labor is not great. The 
wall sheathing is best when made of matched lumber. 

Siding. The siding generally used is lap siding or weather 
boarding. White pine is the wood generally used and is 
regarded as very satisfactory. Drop siding, or so-called 
patent siding, does not give a pleasing effect, although quite 
satisfactory in other respects. Stucco or plastered walls 
are very satisfactory when the plastering is on metal lath. 

Lathing. The lathing should be carefully done, insuring 
uniform spaces between the lath. The girder carrying the 
second floor joists should be set in far enough to enable the 
lath to be nailed on strips and permit the plaster to clinch 
around the lath. The direction of lathing should not be 
changed, as there is a greater tendency to crack the plaster 
when shrinkage occurs. An extra 2x4 should be used in each 
corner so that the lath can be securely nailed in place. 

The Roof. The greater the pitch of the roof the better, but 
a half pitch makes a good roof. Wooden shingles are generally 
used, those of cypress or red cedar being regarded as the best. 
One thousand shingles laid 4 inches to the weather should 
cover 100 square feet; but when laid 43^ inches to the weather 
shingles will make a good roof. There are 250 shingles in a 
bale, which is made 25 layers thick and 20 inches wide. Five 
shingles should make a thickness of two inches. In laying 
the shingles, joints should be broken twice, and plenty of 
nails should be used in nailing them on. Creosote and other 
stains act as a preservative, but painting is not advisable. 
Shingles may be dipped in oil with good results, for which 
about 23^ gallons of linseed oil are required per M. 

The Exterior Finish. The following suggestions in regard 
to the exterior finish may be useful. It should be plain, and 



458 AGRICULTURAL ENGINEERING 

all filigree and turned work should be avoided, as it is not 
durable. The cornice should be broad in order to protect 
the walls. The use of a water table, with an edge under the 
siding, insures a dry wall. Due provision should be made 
above windows and doors for excluding water. Only the 
best paint should be used, and perhaps there is none better 
than pure white lead and linseed oil colored, when desired, 
with the proper tints. 

Plastering. Back -plastering is thought to be very bene- 
ficial in cold, wet climates, although not generally used. 
Back plastering may be either between the studding or on 
the studding, with the second layer of finishing plaster on 
lath nailed to furring strips. The latter is regarded as the 
better method, as there is a tendency for cracks to form from 
shrinkage in the former method. Metal corner beads should 
be used on all exposed plastered corners. The lime for lime 
plaster should be slacked at least 24 hours before adding hair. 
It should be then allowed to stand stacked up at least ten days 
before using. Lime mortar may be made by adding to each 
barrel of lime 3 barrels of sand and 1 to V/2 bushels of hair. 

Hard plaster should be mixed according to the directions 
furnished by the manufacturers. These plasters give a 
harder wall and better protection against moisture. 

The first coat of moisture is called the "scratch coat," the 
second the "brown coat," and the third the "white" or 
"skim" coat. Sometimes the third coat is omitted and the 
walls are left rough or given a "float" finish, which is tinted 
with a calcimine wash. 

The Woodwork. Dust lines should be eliminated as far 
as possible, and for this reason plain finish is desirable. The 
architraves or casings may be mitered or fitted with blocks at 
the corners; the latter does not show the effect of shrinkage as 
badly as the mitered corners. The block placed at the 



FARM STRUCTURES 459 

bottom of the casing to doors is called the plinth. The fol- 
lowing are some additional suggestions: 

1. Ample head room should be provided over stairs. 

2. The sum of the rise and tread of steps should be about 
1734 inches. 

3. "Winders, " or triangular steps,* should be avoided. 

4. A half post should be placed where the banister rail 
joins the wall. 

5. Dimensions of windows are given by the number and 
size of lights. 

6. All sash should be carefully balanced. A good grade 
of cotton cord is satisfactory. 

7. The stop bead should be fastened with screws to per- 
mit of adjustment and the removal of sash. 

8. Doors are made in three grades, A, B, and C. Those 
of standard size and dimensions are known as stock doors. 
Veneered doors are usually more satisfactory than solid ones. 

The Hardware. The butts, locks, knobs, and escutcheon 
plates should be of good quality. The usual grades of hard- 
ware are japanned iron, bronze plated, and solid bronze. 
Much can be added to the appearance of a room by using 
artistic, high-grade hardware. Loose pin, wrought-iron butts 
should be used, as they are stronger than cast-metal butts. 
Mortise locks are to be preferred over rim locks. Hinges 
should be of ample size and should permit the door to swing 
back against a stop on the wall. 

The Finishing Woodwork. All woodwork should be 
sand-papered with the grain before the application of any 
finishing material. Nails should be well set and the holes 
well filled with putty. 

Two coats of hard oil or varnish make the cheapest but 
the least desirable finish. The best finish is five or six coats 
of shellac rubbed down. A wood filler may be used before 



460 AGRICULTURAL ENGINEERING 

the first coat. The final coat should be of the best grade of 
varnish. Floors are usually filled and varnished, or var- 
nished with shellac and waxed. 

Woodwork may be stained with water, oil, or spirit 
stains. Water stains may go deeper but do not preserve 
the wood as well as oil stains. Spirit stains are the most 
expensive and must be carefully applied, as any lapping shows 
badly. 

QUESTIONS 

1. Describe the full frame for houses. 

2. Describe the balloon frame for houses. 

3. What is the objection to a one-and-a-half story house as far as 
framing is concerned? 

4. Describe bridging and state its use. 

5. When is it advisable to put sheathing on diagonally? 

6. What are the relative merits of lap siding and drop siding? 

7. What care should be taken in lathing a house? 

8. Describe the construction and the materials used in building the 
roof. 

9. What are some of the important features of the exterior finish 
of a farmhouse? 

10. Explain what is meant by back plastering. 

11. What care should be used in preparing plaster? 

12. What does scratch coat, brown coat, and skim coat designate? 

13. What is the composition of lime plaster? 

14. What is a float finish to a plastered wall? 

15. Discuss some important features of the woodwork. 

16. What care should be used in selecting the hardware? 

17. State how the woodwork may be finished. 

18. What are the relative merits of the various kinds of wood stains? 



CHAPTER LXXII 
THE SILO 

The Location of the Silo. In locating a silo, the matter 
of convenience should be given first consideration. It should 
be in direct communication with the feed alley in the barn. 
A good location is some four to six feet from the barn and 
joined to the feed alley by a chute extending up the entire 
height of the silo. A door should close the passage-way 
between the barn and the silo; and if the space be made to 
accommodate the silage cart, it will not only make feeding- 
easier but will also provide a good place for storing the cart 
when not in use. 

Nearly all types of modern silos are best located outside 
of the barn. As a rule, the silo does not need the protection 
of a building, and the barn space may be more economically 
used for other purposes. Furthermore, an inside silo is 
inconvenient to fill, as it is difficult to deliver the fodder to 
the ensilage cutter unless large driveways are provided, 
which again are not economical. The odor of silage is 
thought objectionable by some; but when the silo is located 
outside of the building and connected with it only by a chute, 
this objection is overcome. 

The Size of the Silo. The modern silo is round. This 
shape will resist the bursting pressure of the silage to the 
best advantage and permit of a more perfect settling of the 
silage, which is very important. A round silo has two dimen- 
sions, diameter and height. The diameter or cross section 
of the silo should be determined by the size of the herd. 
From \ x /i to 2 inches of silage should be fed from the silo 



462 



AGRICULTURAL ENGINEERING 



each day, after the silo is opened, to keep the silage fresh. 
If a less amount is fed, a growth of mold is quite likely to 
start and travel downward as fast as, if not faster than, 
the rate of feeding. 

The proper height of the silo is readily determined by 
the length of the feeding season. It is an advantage, how- 
ever, to have a deep silo. First, it is ecomonical, as addi- 
tional volume is obtained without adding to the expense of 
foundation and roof. Secondly, the silage depends upon the 
exclusion of air for its preservation, and the extra weight of 
silage in a deep silo promotes settling and assists in this 
direction. Two silos of medium diameter are better than 
one large one, as there may be times when it is desired to 
feed the silage lightly. 

Capacity of silos, and the amount of silage that should be fed daily 
from each. 



Inside 
diameter 


Height 


Capacity, 
tons 


Acres of corn 

of 15 tons 

per acre 


Amount. 

to be fed daily, 

pounds 


12 
12 
12 
12 


30 
32 
34 
36 


67 
74 
80 

87 


4.5 
5.0 
5.3 

5.8 


755 
755 
755 
755 


14 
14 
14 
14 


30 
32 
34 
36 


91 
100 
109 
118 


6.1 

6.7 
7.2 
7.9 


1030 
1030 
1030 
1030 


16 
16 
16 
16 
16 
16 


30 
32 
34 
36 

38 

40 


119 
131 
143 
155 
167 
180 


8.0 

8.7 

9.5 

10.3 

11.1 

12.0 


1340 
1340 
1340 
1340 
1340 
1340 


18 

18 
18 
18 


36 
38 
40 

42 


196 
212 
229 

246 

i 


13.2 
14.1 
15.26 
16.4 


1700 
1700 
1700 
1700 



FARM STRUCTURES 463 

The usual amount of silage fed per day to various classes of stock. 

Kind of stock Daily rations, pounds 

Beef cattle 

Wintering calves 8 months old 15 to 25 

Wintering breeding cows 30 to 50 

Fattening beef cattle, 18-22 months old 

First stage of fattening 20 to 30 

Latter stage of fattening 12 to 20 

Dairy cattle " 30 to 50 

Sheep 

Wintering breeding sheep 3 to 5 

Fattening lambs 2 to 3 

Fattening sheep 3 to 4 

The preceding tables— which give the capacity of some of 
the more common sizes of silos, the number of pounds of 
silage which must be removed daily to lower the surface an 
average of two inches, and an average ration for each of 
various kinds of farm stock — should provide sufficient 
information for deciding upon the size of silo to meet 
ordinary requirements. 

To explain the use of these tables, suppose silage is to 
be fed to 10 head of dairy cows, 8 head of calves, and 40 head 
of beef stock, for 200 days. The amount of silage required 
per day will be about as follows: 

10 dairy cows, 40 lbs. each 400 lbs. 

8 calves, 20 lbs. each 160 lbs. 

40 beef cattle, 20 lbs. each 800 lbs. 

Total silage fed per day 1360 lbs. 

Referring to the first table, it will be found that a silo 16 
feet in diameter will furnish 1340 pounds of silage when 2 
inches is fed daily; hence 36 feet, or 216 times 2 inches, will 
be about the right height. Some allowance should be made 
for settling. 

The Essentials of a Silo. To preserve silage a silo must 
have impervious walls which will not permit air to enter or 



464 AGRICULTURAL ENGINEERING 

moisture to leave. The wall must be strong and rigid enough 
to resist the bursting pressure of the silage, and sufficiently 
smooth on the inside to permit the silage to settle readily. 
In addition to these absolute essentials, there are many 
features which add to the value of a silo and which should 
be considered in its selection. Some of these features are 
as follows: 

1. It is highly desirable that a silo be as durable and 
permanent as possible. All parts should be constructed 
of materials which will insure a long term of service. 

2. The silo should require a minimum expenditure of 
labor and materials for maintenance. This refers to the 
adjustment of parts for shrinkage and expansion, repainting, 
and the substitution of new parts for those which have 
become decayed or otherwise useless. 

3. The silo should have a wall which will prevent as far 
as possible the freezing of silage. 

4. The silo should be arranged in such a manner as to 
be convenient for filling and for the removal of the silage. 
This refers directly to the construction of the doors. 

5. In some cases it is desirable to have a silo which may 
be taken down and moved from one location to another. 

6. A fire-proof silo may have the further advantage of 
serving as a fire wall. 

7. A silo should be sightly and should add to the appear- 
ance of the farmstead. 

8. It is an advantage to have a silo of simple construc- 
tion, which may be erected with the minimum of skilled 
labor, and in the construction of which there is little chance 
for expensive mistakes. 

9. Lastly, the silo of the lowest cost per unit of capacity, 
giving due consideration to the other features of merit, is the 
most desirable. 



FARM STRUCTURES 



465 



If these essentials and desirable features are kept clearly 
in mind, they will assist in comparing the various types of 
silos now in general use. 

WOOD SILOS 

The Stave Silo. The commercial stave silo is in more 
extensive use today, the country over, than any other type. 
When properly made, the walls are air-and water-tight, 
smooth and rigid, insuring 
the preservation of the 
silage. 

The durability of the 
stave silo depends largely 
upon the kind and grade 
of the material used in its 
construction. Redwood, 
cypress, Oregon fir, tama- 
rack, and white and yel- 
low pine are the more 
common kinds of wood 
used, and their respective 
merits and durability rank 
about in the order given. 

The Plain Stave Silo. 
The stave silo made of 
plain dimension lumber, 
without being beveled or 
grooved, is not satisfactory. 
Such a silo is certainly 
cheap, but is very unstable, 
when the staves are matched, and as soon as there is a little 
shrinkage there is a tendency for the staves to fall from place 
into the silo, and then the whole structure collapses. 




Fig. 294. A good stave silo well anchored. 



The walls are not as tight as 



466 AGRICULTURAL ENGINEERING 

Full-Length Stave Silos. Full-length staves are desirable, 
although more expensive. If spliced staves are used, the 
method of splicing should be carefully examined. The 
ends of the staves are fitted together by a U-shaped tongue 
and groove; but the more common method of splicing con- 
sists in inserting a steel spline about 1-16 inch thick in saw 
cuts in the ends of the staves to be spliced. 

The Foundation. The stave silo should be put upon a 
good foundation. The foundation wall need not be wide, 12 
inches being a good width, but it is well that it extend below 
the frost line, or about 2% to 3^ feet. As the silo is likely to 
be partly full during the coldest weather, the frost will not 
be deep near the foundation. Any masonry construction 
may be used for the foundation, but concrete is especially, 
well adapted to the purpose. 

Use of the Pit. It is doubtful if a pit is advisable with a 
stave silo. The increased capacity so secured is economically 
obtained ; but there should not be a shoulder or bench inside 
of the staves, as this will prevent the free settling of the silage. 
If a pit is used to increase the capacity of the silo, and the 
foundation wall is made flush with the staves on the inside at 
the time of erection, it will be difficult to keep the silo on the 
foundation as shrinkage occurs. 

Anchoring and Guying. The stave silo is a light struc- 
ture and when empty is more or less at the mercy of the wind. 
To guard against any possible damage from this source, it 
should be carefully anchored to the foundation and guyed or 
braced in all directions. The anchors to the foundation 
should be at least four in number, and may be made of bars 
extending into the masonry and bolted to the staves above. 
The top of the silo should be carefully braced to any adjoin- 
ing buildings. The guy wires or cables should run in 
pairs to posts and buildings in opposite directions. These 



FARM STRUCTURES 467 

guys are more effective when extending out some distance 
from the base of the silo. The importance of this anchoring 
and bracing is urged upon all. 

The Roof. Every silo should have a roof: (1) It adds to 
the appearance; (2) it strengthens and protects the staves; (3) 
it is a big factor in preventing freezing; (4) it makes the silo a 
pleasanter place in which to work. No attempt should be 
made to secure ventilation; in fact, an attempt should be made 
to retain the warm air in the silo as far as possible. Pre- 
pared roofing of good quality makes a durable silo roof. It is 
easily fitted to a conical form. 

The Doorway. All commercial silos at the present time 
have a continuous doorway, across which there are no obstruc- 
tions except the crossties. This type of doorway offers 
certain advantages in removing the silage, and is just as 
satisfactory in other respects as the individual doorway. In 
selecting a silo, it is well that an examination be made of the 
door-fasteners to see whether or not the door makes a per- 
fectly air-tight joint with the frame. 

The Minneapolis Silo. The Minneapolis silo, or so- 
called panel silo, is constructed of pieces of planks about 2 
feet long, matched at the sides and beveled at the ends, set 
into vertical studding. The whole is then bound together 
by hoops, which require practically no adjustment, as there is 
little shrinkage lengthwise of the grain. Defective pieces in 
this silo may be replaced by cutting them out, driving down 
the pieces above, and inserting new ones at the top. This 
type of silo is very rigid and stable. 

MASONRY SILOS 

The Concrete Silo. Concrete is one of the best materials 
for silos. It is very important to make the concrete silo wall 
impervious to air and water. The more common method of 



468 AGRICULTURAL ENGINEERING 

doing this is to treat the inside of the wall, as soon as the 
forms are removed, with a wash of pure cement and water 
reduced to the consistency of paint. This wash thoroughly 
seals the pores of the walls and prevents the loss of mois- 
ture and the admission of air. A coat of coal tar has been used 
with good results, and there are many patented compounds 
on the market which ought to be entirely satisfactory. In 
several cases where no attempt was made to seal the walls the 
juices of the silage apparently accomplished that result, after 
two or three fillings, but this should not be relied upon. 

Reinforcement. Another common mistake is the lack of 
reinforcement or the improper use of reinforcement. The 
bursting pressure of silage is considerable, about 11 pounds 
per square foot for each foot of depth, as an average; and this 
pressure must be fully cared for or the walls are sure to crack. 

A mixture of one part of cement, two of sand, and four of 
broken stone or screened gravel ought to make a good silo 
wall. If good natural gravel and sand are at hand, a mix- 
ture of one to five will be satisfactory. 

The Block Silo. There are two methods of using con- 
crete: (1) in the form of blocks, which are made and cured 
before being laid in the wall; (2) the monolithic wall, requir- 
ing the use of forms. The first method involves a large 
amount of labor in making and handling the blocks and lay- 
ing them in the silo wall. So much labor is involved that 
it is likely to be the most expensive item of the entire cost. 
The use of forms in the monolithic construction dispenses 
with a large part of the labor, but in turn offers some serious 
disadvantages. To obtain good, smooth walls, rather 
expensive forms must be made; and as the silo reaches some 
height, the forms are difficult to handle without expensive 
scaffolding and hoisting apparatus. 



FARM STRUCTURE 



469 



Monolithic Silos. The solid wall does not offer serious 
objections in permitting the freezing of the silage, especially 
if provided with a good, 
tight roof. The concrete 
silo blocks are nearly al- 
ways made to contain an 
air space, and double forms 
may be used in the mon- 
olithic construction, mak- 
ing a double wall. When 
air circulation is restricted 
in the dead-air space by 
horizontal partitions about 
every three feet of height, 
the double wall is perhaps 
the most satisfactory, as 
far as frost-proof qualities 
are concerned. 

The cost of a concrete 
silo will depend largely 
upon local conditions. The 
cost of sand, gravel, and 
labor are the deciding factors. Under usual conditions, the 
cost should not greatly exceed the cost of a first-class wood- 
en silo. No attempt will be made here to discuss the con- 
struction of forms. 

The Hollow Clay Block, or Iowa Silo. In general, this 
silo consists of a wall of vitrified clay building blocks reinforced 
with steel laid in the mortar joints. The roof is made of 
concrete, and the silo has a reinforced concrete door frame. 

Description of the Blocks. The blocks are hard-burned 
building blocks, and may now be had curved to the curvature 
of the silo wall, making a smoother wall on the inside. These 



o^S 



monolithic silo 
crete roof. 



470 



AGRICULTURAL ENGINEERING 



blocks are of the same material and have the same character- 
istics as brick; in fact, in certain localities they are called 

hollow brick. If these 
blocks are of good mate- 
rial and hard-burned they 
are very durable. 

The 4x8xl2-inch block 
has proven to be a very 
satisfactory size. Larger 
blocks are too large to 
handle with one hand, and 
smaller ones require more 
labor in laying. These 
blocks are laid on edge, 
making a four-inch wall. 
The Cement Wash. If 
curved blocks are used 
and care is used in point- 
ing and filling the mortar 
joints, the wall will be suf- 




Fig. 296. The Iowa silo made of hollow ficieiltly SmOOth On the Ul- 
vitrified Cay building blocks or tile. ^ ^ om j t t he plastering. 

To seal the mortar joints and make the whole impervious, 
a cement wash should be applied before the mortar becomes 
hardened. 

Reinforcement. The entire bursting pressure of the 
silage should be carried by steel wire imbedded in the mortar 
joints. Number 3 wire has been found to be a very satis- 
factory size. It is small enough not to interfere with the 
laying of the blocks, and fewer strands are required than of 
the smaller sizes. This wire should be unannealed, and may 
be straightened to the curvature of the silo by drawing it 
through a piece of pipe bent to the proper angle. 



FARM STRUCTURES 



471 






297. The wall of the Iowa silo. 



The Doorframe. The doorframe is continuous with the 
crossties, which are at least 42 inches apart. The jambs are 
simply reinforced concrete beams. The crossties contain 
reinforced bars of equal strength to the horizontal reinforce- 
ment in the wall proper, and extend back to each side into 
the open space in the 
blocks, to obtain a good 
grip upon the wall. The 
blocks containing the bars 
are completely filled with 
concrete. The bars across 
the doorway are covered 
either by blocks filled with 
concrete or by concrete 
alone. 

The Foundation. The 
foundation for the Iowa 

silo may be of any good masonry construction. It is im- 
portant that the footings be placed below the frost line. 
Concrete and hard-burned blocks have been used with equal 
success. A 16-inch footing and a 6- to 8-inch wall are all that 
is required. The space inside of the wall may be economic- 
ally added to the capacity of the silo. The extra expense 
involved is simply that of throwing out the earth within 
the foundation walls. 

Floors. Although a floor is not absolutely necessary, 
it adds much to the convenience of removing and cleaning 
up the silage at the finish. Four inches of concrete will make 
an excellent floor. Paving blocks or sidewalk blocks have 
been used successfully. A few floors have been made by 
laying the hollow blocks flat and plastering with cement on 
top. 



472 AGRICULTURAL ENGINEERING 

The Roof. The roof of the Iowa silo is constructed of 
concrete, making this part as durable and lasting as the rest 
of the silo. The cornice is made of blocks laid flat-wise, 
and the center is made of two and one-half to three inches 
of concrete placed upon a conical form. The conical shape 
is very desirable for a concrete roof, as nearly all of the 
reinforcement may be confined in the base of the cone. If 
thoroughly reinforced at this point, there is little opportunity 
for failure. A window must be provided in the roof for 
filling the silo. 

QUESTIONS 

1. Where should the silo be located? 

2. What are the factors that determine its diameter and height? 

3. How does the capacity of a silo vary with its diameter? How 
does the amount of material in the walls vary with the diameter? 

4. How much silage should be fed from the surface each day? 

5. What are the essentials of a good silo? 

6. Discuss the construction of the stave silo. 

7. Upon what does the durability of the stave silo depend? 

8. What are the merits of the plain-stave silo? 

9. How are silo staves spliced? 

10. Discuss the construction of the silo foundation. 

11. Can a silo pit be used to increase the capacity of a stave silo? 

12. Describe how a stave silo should be anchored and guyed. 

13. Describe two types of doorways for silos. 

14. Describe the construction of the Minneapolis or panel silo. 

15. What is necessary to make a satisfactory silo wall of concrete? 

16. How should the walls be reinforced? 

17 What kind of mixture should be used in preparing the concrete? 

18. What are the advantages and disadvantages of the cement- 
block silo? 

19. Describe the monolithic concrete silo. 

20. Describe the hollow clay block or Iowa silo. 

21. What are the desirable features of clay blocks for silos? 

22. How may the wall be made impervious? 

23. How can the clay-block silo be carefully reinforced? 

24. Describe the construction of the doorframe, the foundation, 
the floor, and the roof of the Iowa silo. 



CHAPTER LXXIII 
THE IMPLEMENT HOUSE AND THE SHOP 

The Value of an Implement House. It is not economical 
to have the machinery stored in the general barn or in any- 
expensive building. The implement house or shed need 
only provide protection from the weather. Barns do not 
furnish good storage on account of the dust which must 
necessarily be about and because of the inconvenience. 

The Location. The best location for the implement 
house is that which makes it a central feature of the farmstead 
group. A location about half-way between the house and 
barn and a little to one side of a direct line between the two 
buildings seems to be the most generally desirable. The 
implement house in this connection is thought of as provid- 
ing storage for the farm wagon and other vehicles used upon 
the farm. Its location should be such that it will be con- 
venient to hitch to a vehicle or implement upon coming from 
the barn with a team and enable the driver to pass as directly 
as possible to the field or to town without extra travel. 

The Size. The size of the house will depend on the 
number of implements to be stored. It is not best, however, 
to have the building too wide, as it will be inconvenient to 
remove certain implements on account of those stored in 
front, which arrangement will be necessary to utilize all of 
the space in a wide building. In preparing to build an 
implement shed, it would be well to determine the floor 
space required for each implement and then plan on having 
a certain place reserved for each. This arrangement will 
save much time in handling the implements. 



474 



AGRICULTURAL ENGINEERING 



The Foundation. The foundation need not be heavy; a 
6-inch concrete wall will be ample if it be widened to 8 
to 12 inches for the footing. Piers are very satisfactory for a 
frame building. If the walls of the house are to be of masonry 
construction, the foundation should extend below the frost 
line. 

The Floor. A dry earth floor is customary in the imple- 
ment house. A wood or concrete floor in the carriage or 




Fig. 298. A convenient open-front implement house. 

automobile room would be desirable, but not a necessity. 
Concrete is best, as boards or planks are likely to provide a 
harbor for rats and other vermin. 

The Walls. The walls need only provide protection 
from the sun, moisture, and wind. Either drop or matched 
siding or plain boards with battens may be used. The plain 
boards, as usually erected, make a tighter wall after they have 
been in use for a time, and they last longer. Concrete makes 
a very good wall for an implement house and is not unduly 
expensive if the wall is not made too thick. A four-inch wall, 
is sufficient if placed upon a good foundation, and, if the wall 
be long, it may be stiffened by an occasional pilaster. In 
like manner a four-inch brick wall will be found to be quite 



FARM STRUCTURES 475 

satisfactory. Hollow clay building blocks, when such mate- 
rial of good quality can be readily obtained, make a very 
desirable wall for the implement house. Blocks are much 
cheaper than brick and more wall can be laid in a given time. 

One advantage of the masonry walls is that they are more 
nearly dust-proof than a single-board wall, and the imple- 
ments they protect will present a better appearance at all 
times. This feature is of little advantage except in the care 
of the buggies or carriages. If a good, tight wall be provided, 
it will not be necessary to cover the vehicles with a cloth, as 
is practiced by many who take pride in the appearance of 
their turnouts. 

The Roof. The roof can well be made of an assortment 
of materials. Roofing boards with battens make a good, 
cheap roof for a narrow building, especially those with the 
roof sloping one way only. A shingle roof, of at least one- 
third pitch and of a good quality of cedar or cypress shingles, 
is quite satisfactory, but is not nearly as dust-proof as some 
of the other forms of construction. A layer of building paper 
over the sheathing, as commonly used in house construc- 
tion, would improve it in this respect. Prepared roofing 
makes a very desirable roof for an implement house, as it is 
perfectly tight and when a good quality is used its durability 
will compare favorably with shingles. Care should be 
taken to make the walls tight between the roof and the plate, 
where it is desired to have a dust-proof building. 

The Framework. The framing of an implement house 
is not difficult. If a gable roof is used, 2x4 rafters placed 
two feet on center will be sufficient for a building 16 feet wide, 
if given at least one-third pitch. If the house has a shed roof, 
2x4 rafters will be sufficient for a 12-foot span with a one- 
third pitch. A wider building should have 2x6 rafters, if the 
building is to retain its shape. If the house is to have a sec- 



476 



AGRICULTURAL ENGINEERING 



ond floor, and the joists do not support the plate and prevent 
the thrust of the rafters from spreading the building, there 
should be several diagonal braces from the plate to the joist. 
The implement house may be built with one side open. 
This is a convenient arrangement, but does not keep out the 
dust; and the chickens of the farm, if not confined, will find 
the machinery a very satisfactory roosting place, much to the 
detriment of the machinery. If large doors are provided, it 
L 48-0' 



-pQty&rs&lGs. °cff9!yz. A°?/y^?x 



^■Corfcrof-e )sa// 



,-'*- 



i J°1/j Cor7cfo/o p/'ors 

S4~-S4~ base. -' 



■ 4"-6 support exfe/?as 
ft/// /ength ofb/c/g. 




Fig. 299. A cross section of the house shown in Fig. 298. 

will not be inconvenient to store the various machines; in 
fact, one entire side may be made up of doors hung on a 
double track, half of them being on the outside track and the 
other half on the inside track. This arrangement permits of 
the doors being opened at any point. 

It is often an advantage to have a second floor, to accom- 
modate the light implements, such as the cultivator, stalk 
cutter, corn planter, etc. The implements may be drawn 
up on a runway by means of a horse and a rope and pulley. 



FARM STRUCTURES 477 



THE FARM SHOP 



Utility. From an extensive investigation on the life and 
care of farm machinery in Colorado, it is reported * that 71.36 
per cent of the farm machinery on farms not having shops 
needed repairs, while only 59.25 per cent on farms having 
shops needed repairs. These facts are taken by the writer of 
the bulletin to mean that the farm shop has a "real value 
beyond the occasional emergency job." 

It is well-nigh impossible to maintain the efficiency of the 
farm equipment without a liberally equipped shop. It is 
not so much a matter of saving a few dollars by doing repair 
jobs, as it is a matter of getting the work done. 

The Location. The location of the farm shop should be 
similar to that described for the implement house; indeed 
it may be made a part of or an addition to the implement 
house, as its usefulness is largely directed toward the farm 
machinery. If a forge is installed, due thought should be 
taken of danger from fire. The location may also be selected 
with reference to any small stationary engine or other source 
of power the farm may have, so that the same power may 
be available for tools in the shop. 

The Size. The farm shop may be built large enough to 
house a wagon or similar implement, or it may be just large 
enough to contain a bench and tools and furnish the minimum 
amount of working room. A shop 16 by 20 feet will be 
needed to accommodate large machines. On the other hand, 
a shop 8 by 10 feet will house a bench, a forge, and an anvil, 
and may be considered the minimum size for practical pur- 
poses. 

Construction. The house should afford comfortable 
quarters for work during cold weather. If made wind- 



*Bulletin No. 167, Colorado Agricultural Experiment Station. 



478 AGRICULTURAL ENGINEERING 

proof, a stove may be put in. If a forge be installed, it and 
the anvil should be placed on earth, concrete, or some other 
kind of fire-proof floor. The exterior of the shop should be 
made to conform to the style of the other buildings about the 
place. In buying the equipment, care should be exercised to 
get good, standard tools of known merit. 

QUESTIONS 

i. Why have a separate implement house on the farm? 

2. Discuss the best location for an implement house. 

3. How may the size of the implement house be determined? 

4. Discuss the construction of the foundation, the floor, the walls 
and the roof of the implement house. 

5. Describe how the frame of an implement house may be con- 
structed. 

6. To what use may the second floor of an implement house be 
put? 

7. Why is a repair shop needed on a farm? 

8. Where should the farm shop be located? 

9. What are satisfactory dimensions for a farm shop? 
10. Discuss the construction of a farm shop. 

LIST OF REFERENCES FOR FARM STRUCTURES 

Building Trades Handbook. 
Farm Buildings. 

Radford's Practical Barn Plans. 
Barn Plans and Outbuildings. 
The Farmstead, I. P. Roberts. 
Tuthill's Architectural Drawing. 
Architectural Drawing, C. F. Edminster. 

Practical Suggestions for Farm Buildings, U. S. Dept. of Agri., 
Farmers' Bui. 126. 

College Farm Buildings, Mich. Agri. Exp. Sta., Bui. 250. 
Circular No. 15, Division of Forestry, U. S. Dept. of Agri. 
Architects' and Builders' Pocket Book, F. E. Kidder. 
Mechanics of Materials, Church. 
Materials of Construction, J. B. Johnson. 



FARM STRUCTURES 479 

Farm Poultry House, Bui. 132, Iowa Agr. Exp. Sta. 

Building Poultry Houses, Cornell Bui. 274. 

Poultry House Construction and Yarding, Mich. Bui. 266. 

Poultry House Construction, Wisconsin Bui. 215. 

Poultry Architecture, George B. Fisk. 

Location and Construction of Hog Houses, 111. Agr. Exp. Sta., Bui. 
109. 

Hog Houses, U. S. Dept. of Agr., Farmers' Bui. 438. 

Portable Hog Houses, Wis. Agr. Exp. Sta., Bui. 153. 

Suggestions for the Improvement of Dairy Barns, 111. Agr. Exp. 
Sta., Cir. 95. 

Economy of the Round Dairy Barn, 111. Agr. Exp. Sta., Bui. 143. 

Sanitary Cow Stalls, Wis. Agr. Exp. Sta., Bui. 185. 

Plank Frame Barn Construction, John L. Shawver. 

Hodgson's Low Cost American Homes. 

Modern Silo Construction, la. Agr. Exp. Sta., Bui. 100. 

The Iowa Silo, la. Agr. Exp. Sta., Bui. 117. 

Concrete Silos, Universal Portland Cement Co. 

Specifications, International Correspondence School Text. 

Ventilation, F. H. King. 

King System of Ventilation, Wis. Agr. Exp. Sta., Bui. 164. 



PART EIGHT— FARM SANITATION 



CHAPTER LXXIV 
THE FARM WATER SUPPLY 

The subject of farm water supply easily divides itself into 
the following heads, each of which will be discussed in turn: 

1. The source of supply. 

2. The quantity required. 

3. The pumping plant. 

4. The distribution system. 

5. The storage tank or reservoirs. 

The Source of Water Supply. The first requisite of a 
suitable source of water supply is that it shall furnish pure 
water. It is fully realized at the present time that one of the 
most important places where the health of the family is to 
be guarded is the water supply, for so many diseases are 
traceable to polluted water. It is not so essential that water 
be pure chemically as that it be free from all germs which 
may cause trouble in the human system. Water may con- 
tain a considerable percentage of certain mineral salts and yet 
be quite healthful. On the other hand, water may be quite 
free from all salts or mineral matter, be clear, cool, and spark- 
ling, and still be filled with deadly typhoid or other disease 
germs. 

Wells. The well is the most common source of water 
supply for the farm. Wells are divided primarily into two 
classes, with reference to their depth, as shallow and deep 
wells. The shallow well refers to those either dug by hand 



FARM SANITATION 



481 



or bored with a common well auger. These wells are usually 
of considerable diameter in order that there may be a reser- 
voir for a quantity of water within the well itself. The shallow 
well is the one most easily contaminated and is the one which 
should be most carefully protected. It is best that the well 
be located at some distance from any leaching cess-pool, 
privy, or manure heaps. It is difficult to state just how far 
away, as some soils are much more open than others and the 
impurities will travel a correspondingly greater distance 




Fig-. 300. A sketch showing hew the water of a shallow well may be- 
come contaminated from manure yards and cess-pools. (Kansas Exp. Sta. 
Bui. 143.) 

through them. Then, again, drainage lines become quite 
thoroughly established in the soil in certain directions; and 
if the well and a source of contamination should happen to be 
placed in one of these seepage lines, the contamination would 
take place at a much greater distance than otherwise. It is 
best, however, that the well, especially a surface well, be 
located at least 100 feet from any disease-laden filth. 

Much can be accomplished in providing protection against 
contamination from the surface: ,(1) The curb or well wall 



482 AGRICULTURAL ENGINEERING 

should be made water-tight for some distance below the sur- 
face; (2) the well should have a good, tight platform or cover; 
and (3) the surface of the ground should be raised about the 
well so that all surface drainage will be away from the well. 

Surface wells are the cheapest of all wells. The cost per 
foot, with curb, varies from 50c for a 12-inch hole, to 
over $2 for a well four feet across and walled with loose 
stone. A good platform cemented over will cost about $10. 
It might be mentioned here that concrete makes an ideal 
pump platform and will last indefinitely. One slab can be 
made loose to furnish access to the well. 

Deep wells are usually either driven or drilled. A driven 
well is made by attaching a sand point to a casing, usually 134 
inches in diameter, and simply driving it into the ground 
until the point reaches a water-bearing stratum of gravel or 
sand. The sand point is made of perforated brass over an 
iron frame, through which the water will readily pass into the 
casing. The pump cylinder is made a part of the casing, and 
valves are set at proper places by expanding rubber rings to fit 
the casing. Driven wells never extend through a rock stratum. 

Drilled wells are made by operating a drill inside a casing 
which sinks as the drill provides the way. The mud and chips 
of stone are removed by pumping a stream of water through 
the drill and out through the casing. If the casing is of small 
diameter, about two inches, with the cylinder a part of it, it 
is called a tubular well. The usual diameters for drilled 
wells are 6 and 8 inches. These diameters permit the pump 
cylinder and piping to be entirely independent of the well 
casing. The usual cost of tubular wells, with casing, is $1 
to $1.50 per foot. Drilled wells range in cost up to $6 per 
foot for an 8-inch well drilled in granite rock. 

Deep wells are rightly considered a better source of water 
supply than shallow wells, yet they are by no means entirely 



FARM SANITATION 



483 



free from contamination. Occasionally drainage lines are 
so thoroughly established in the soil and through fissures in 
the rock that the water of the deep wells may be contami- 
nated from the surface. 

Springs are sometimes used as a source of water supply. 
It is best that the spring discharge at as high an elevation 
as possible in order that there may not be many habitations 
above it. When springs furnish water from some depth, the 




Fig. 301. An improved spring showing how it may be protected from 
surface water. 



water is quite sure to be free from all organic matter. In 
considering a spring as a source of water supply, it should be 
definitely known that a sufficient amount of water will be 
furnished throughout the year. Most springs are irregular 
in their discharge and at times furnish little or no water. 

The ideal location for a spring is at an elevation above the 
farmstead, to which the water may be led in pipes and perhaps 
allowed to flow constantly, the surplus being wasted. If the 
spring is below the farmstead, yet high enough to permit a 



484 AGRICULTURAL ENGINEERING 

waste to still lower levels, and if the flow is ample a hydraulic 
ram or pumping plant can be used. 

Brooks or running streams form another source of water 
supply, but should be carefully considered before using. A 
close inspection should be made to determine whether or not 
the stream is in any danger of pollution by surface washing 
from manured fields or house and farm yards. River water 
is quite apt to be turbid during the flood season. Streams 
flowing through uninhabited or uncultivated upland will fur- 
nish water of the most desirable character. 

Lakes usually furnish water that is clear and potable, ow- 
ing to the fact that the water is purified by coming to rest and 
allowing the impurities to settle. Often, in settled commu- 
nities, where the practice is not forbidden by law, the banks 
of lakes are used as a dumping ground for all sorts of 
refuse. Such practice prevents the use of the water for 
human composition. 

Drinking water obtained from a stream or lake should be 
filtered. A box filled with sand and gravel or charcoal 
through which the water must pass is the most common type 
of filter in use. 

The Quantity Required. Care must be taken, in selecting 
a water supply, to determine that the quantity of water 
available will be sufficient not only for all present needs but 
also for any increased demand that may be foreseen. The 
daily requirements must also be taken into account when 
planning a reservoir or storage tank. 

The greater part of the water consumed on the farm is 
required by the live stock for drinking purposes and by the 
household. The house requirements depend largely on 
whether or not plumbing fixtures are installed. The amount 
consumed per day by each of the various farm animals is 
about as follows: A horse, 7 gallons; a cow, 6 gallons; a 



FARM SANITATION 485 

hog, 3 gallons; and a sheep, less than 3 gallons. Dairy cows 
giving milk require additional water in proportion to the 
amount of milk given. Where sanitary plumbing is installed, 
about 20 gallons of water per day will be consumed for each 
person, large or small, and for all purposes, including the 
laundry. 

QUESTIONS 

1. Into what divisions or heads may the subject of farm water 
supply be divided? 

2. What are the principal sources of water supply on the farm? 

3. Explain how surface and deep wells are dug or drilled and curbed 
or cased. 

4. Describe how the well should be protected from contamination. 

5. When may springs, running water, and lakes be used as a source 
of water supply? 

6. How may the daily consumption of water b^ estimated? 

7. Estimate the amount of water required on the home farm. 



CHAPTER LXXV 
THE PUMPING PLANT 

The pumping plant for a farm water supply consists of 
some form of motor and a pump. Although many pumps are 
still operated by hand, a modern water system can scarcely 
be considered complete without a motor, for the simple reason 
that man caimot compete with motors in the production of 
power. A specific instance is on record where a gasoline 
engine pumped the water for a dairy herd at a cost of one cent 
per day for gasoline; whereas two hours of hand labor, worth 
at least 20 cents per hour, were formerly required. It is a 
waste of money to pump by hand if a large quantity of water 
is required daily. The forms of motors now in use for pump- 
ing purposes are the windmill, the gasoline engine, and, in a 
few instances, the hot-air engine and the water wheel. 

Sources of Power. A windmill is better suited by far 
for the pumping of water than for any other purpose. The 
power of a windmill is quite limited; yet an average pump 
requires little power. Furthermore, the power is quite irreg- 
ular, but if a storage reservoir is used this undesirable feature 
is easily overcome. As discussed in a previous lesson, the 
cost of windmill power consists of the interest on the invest- 
ment, and the depreciation and maintenance. 

The gasoline engine is well adapted to the pumping of 
water. As has been stated, the average pump requires very 
little power, and the gasoline engine has the advantage over 
other heat motors in that it is very economical in small units. 
A series of tests made a few years ago at the Iowa State Col- 
lege indicated that 20 barrels of water could be pumped 



FARM SANITATION 



487 



against a head of 100 feet, or, in other words, lifted that dis- 
tance, for every day in the year, at a cost of less than 
five dollars for gasoline. Again, 
the gasoline engine does not need 
constant attention. If anything 
goes wrong, the engine will likely 
stop without doing damage. A 
float or other safety device may 
be connected with the igniting 
system or fuel supply in such a 
way as to stop the engine when a 
certain height of water in the 
supply tank or a certain pressure 
has been attained. 

Hot-air engines have little to 
commend them other than their 
reliability and safety. Solid fuel 
of almost any kind, as well as oil 
and gas, may be used. They are 
not economical of fuel, but where 
the fuel is cheap they may be oper- 
ated at a reasonable expense. 

Water wheels can be used only in 
rare instances, and will not be dis- 
cussed for this reason. There are, 
no doubt, many places where they 
may be used to advantage. 




Fis 



302. A good type of 
three-way or underground 

The pump is as important a ™- a ™- r fX P cyiCefto 

throw the windmill out of 
gear when a certain pressure 
has been reached. 



part of the pumping plant as the 

motor. Pump troubles and repairs 

are always very annoying, and a pump of good constructio n 

and properly installed is always a good investment. The 

amount of power required to operate a pump is small, as will 

be shown by the following table : 



488 



AGRICULTURAL ENGINEERING 
Pump tests. 



No. 
test 


Kind of cylinder 


03 

M 

o 

w 


Lift 


Gals, per 
min. 


H. P. 

used 


Hydrau- 
lic H. P. 


Effi- 
ciency 
percent 


2 


2 Yi ", brass lined 


8 


50 


5.81 


.195 


.0732 


57.0 


3 


2}4", brass lined 


8 


100 


5.33 


.255 


.1343 


52.5 


8 


3 ", brass body 


S 


50 


8.01 


.21 


.1019 


48.4 


9 


3 ", brass body 


8 


100 


7.8 


.395 


.1965 


49.6 


26 


4", plain iron 


S 


50 


10.0 


.52 


.126 


21.2 


17 


4", plain iron 


8 


100 


10.3 


.75 


.259 


34.7 



Important Features of a Pump. In selecting a pump, the 
service to be required of it should always be kept in mind. • If 
the water is only to be lifted from a shallow well and delivered 
into a pail or tank under the spout, any common lift pump 
may be used. A lift pump is one in which no provision is 
made for forcing or lifting the water higher than the pump 
spout. Force pumps have the pump rod packed, making it 
water-tight. 

One of the most important parts of a pump is the cylinder, 
of which there are three common grades on the market; viz., 
plain iron, iron with brass lining, and brass-body cylinders. 
The first is the cheapest, but is the least durable, as iron 
easily corrodes. Brass-lined cylinders are quite satisfactory, 
in that the iron supports and protects the brass, which is a 
soft metal. Brass-body cylinders are used where corrosion 
will be unusually rapid and where space is limited. Often, in 
drilled wells of small diameter, brass-body cylinders with the 
caps screwed inside of the barrel instead of on the outside 
are installed, thus permitting the use of a cylinder of rela- 
tively large diameter. Brass-body cylinders will not stand 
severe service. When dented, they are almost past repair, 
and the screwing of the caps to the thin barrel is difficult, be- 
cause little material is provided for the threads. Porcelain- 



FARM SANITATION 



4S9 



lined cylinders are used where the water contains elements 
that corrode iron and brass. 

Plungers are constructed to suit the lift under which they 
are to work. If the lift has but a few feet, one plunger 
leather which expands out toward the cylinder walls, making 
a water-tight fit, will be sufficient; but if the well is deep or 
the water is to be lifted against pressure, as many as four 
leathers will be found best. 




Fig. 303. Some common types of pump cylinders. 1 is of plain cast 
iron, 2 is galvanized, 3 is porcelain lined, 4 and 5 are brass lined, and 
6 is an all-brass cylinder. 



The valves are another important part of a pump. 
They should be designed to resist wear and to require the 
minimum of attention. There are at least four types of 
valves used in farm pumps. The hinge valve, made with a 
metal weight on a leather disk and attached at one side, is 
used where the lift is not great. It is a simple valve and the 
cheapest, but is not well suited for high pressures. Poppet 
valves are those which lift directly from the seat, and are 
made with one or three prongs to guide the valve to its seat. 
These valves are the easiest to repair. Ball valves are used 



490 AGRICULTURAL ENGINEERING 

where the water is likely to contain sand, as the seat of the 
ball valve is usually quite narrow and the sand is not given 
an opportunity to lodge upon it. 

The Stock. The part of the pump visible above the plat- 
form is known as the stock, and is made in a variety of styles. 
The simplest form is the lift pump, which, as a hand pump, 
was formerly made with wooden stocks, but now cast iron is 
generally used. The next simplest is the force pump, made 
after the plan of the common lift pump, with provision to pre- 
vent leakage about the pump rod. 

Where the water is to be pumped into a storage tank and 
the pump is in a more or less exposed location, a three-way 
pump may be used. It provides a valve that enables the 
water to be pumped out of the spout, or delivered through an 
underground pipe to the storage tank, or drawn from the tank 
through the spout. 

In cold climates a pump should be protected against freez- 
ing by surrounding the valves with a frost-proof well pit and 
providing for the drainage of the pump stock. If a com- 
pressed air system of water storage is installed, a special 
pump must be provided which will pump a little air with the 
water; or a separate air pump must be used. 

QUESTIONS 

1. Is the pumping of water by hand ever economical? 

2. What are the principal sources of power for pumping water? 

3. Discuss the relative merits of the gasoline engine, the windmill, 
and the hot-air engine, for pumping water. 

4. Describe the difference between a lift pump and a force pump. 

5. What are the relative merits of the different kinds of pump 
cylinders? Pump valves? 

6. Describe the three-way pump and its use. 

7. How should a pump be protected from freezing? 



CHAPTER LXXVI 
DISTRIBUTING AND STORING WATER 

Water Pipe. After a consideration of the source of sup- 
ply for a farm water system, the quantity of water required, 
and the pumping plant, the next thing to be considered is the 
distributing system or piping by which the water is conveyed 
to points where needed and to the reservoir for storage. For 
farm water systems, wrought-iron or steel pipe with screwed 
joints is universally used. Cast-iron pipe with leaded joints 
is used for pipes four inches or larger in diameter, but pipes 
this large are seldom required in connection with farm sys- 
tems. Wrought-iron or steel pipes placed underground 
should always be galvanized or coated with asphalt to pro- 
tect them from rust. They are commonly galvanized. 

Sizes of Pipe. The two sizes of pipe in general use are 
three-fourths and one inch. In rare instances half-inch pipe 
may be used, but the flow of water through this size pipe is 
very slow, especially if a long length is used. The friction 
between the water and the walls of the pipe counteracts the 
pressure which causes the water to flow. The following 
table, taken from the Cyclopedia of American Agriculture, 
indicates how great the friction is with small pipe. 

Referring to the table it is seen that if a pump is deliv- 
ering four gallons per minute through a length of 3^-mch pipe 
500 feet long, it must do so against a friction head or pressure 
of 270 feet of water. This would be impractical. Although 
the table does not include %-inch pipe, the loss of pressure 
due to friction would lie between the values given for %- and 
1-inch pipe. The average farm pump will discharge about 



492 



AGRICULTURAL ENGINEERING 



5 gallons per minute, which would require the use of pipe at 
least 1 inch in diameter or larger for mains, and the smaller 
sizes should only be used for branches. In many cases the 
pump is overloaded by using pipe of insufficient size. 

Flow of water in pipes. 



Flow in gallons per minute 


Head in feet lost by friction in each 100 foot of length 




l^-inch pipe. 


1-inch pipe. 


0.5 
1.0 
2.0 
4.0 
10.0 


4 

7 

17 

54 

224 


.03 
.07 

1.6 

5.3 

9.3 



Piping Systems. There are two general types of under- 
ground piping systems on farms. The first of these is known 
as the " ramified " system, which consists of a main laid in the 
shortest possible line from the water supply to the farthest 
hydrant, with branches extending out on either side like 
branches of a tree. The one objection to this arrangement 
is that the water in the branches is dead unless constantly in 
use. There is, however, a saving in the cost of pipe, as 
smaller sizes may be used for the branches. The second type 
is known as the "circulatory " system, in which the main pipe 
passes to all hydrants and the extreme ends are connected, if 
possible. With this system the water does not stagnate in 
any part. 

In planning the distributing system, it is best to provide 
large mains if fire protection is desired. Valves should be 
put in various parts so that a disturbance in one part will not 
interfere with the use of the rest of the system. Often it 
can be arranged to have the fresh water, as pumped, pass 
through the house, thus providing drinking water. 



FARM SANITATION 



493 



Water Storage. The size of the storage tank and reser- 
voir will depend primarily on the kind of power used for 
pumping. It is customary to provide in storage a supply to 
last five days when the pumping is done by a windmill; and 
when a gasoline engine is used, the storage capacity may be 
reduced to a two-days' supply. 

The two general methods 
of storing water are by the use 
of the elevated tank and the 
pressure tank. The first of 
these depends upon gravity to 
force the flow of water, and the 
second uses compressed air. 

Towers and Tanks. The 
ideal location for an elevated 
water reservoir is upon some 
natural eminence. If the emi- 
nence is high enough to justify 
it, the reservoir may be built 
beneath the surface like a cis- 
tern, thus insuring that the 
water will be kept cool. If 
there is no natural means of 
securing elevation, the tank 
must be placed upon a tower 
or in a building. The height 

of the tower will depend upon the height of the buildings to 
which the water is to be delivered and upon the pressure 
desired. The tower may be made of steel, wood, or masonry. 
Masonry tanks are best, but often the cost is prohibitive. 

A tank on a tower is exposed more or less to the weather 
and will give trouble from freezing. This is especially true of 
steel tanks. Wooden tanks are preferred over steel for out- 





■■- — tf 

1 A n8 


^ 





Fig. 304. An Iowa silo with a 
masonry water supply tank on 
top. 



494 



AGRICULTURAL ENGINEERING 



side locations, as they are easier to erect and are cheaper. 
Cypress is considered one of the best woods for tank construc- 
tion, and may be expected to last 15 to 20 years. 

Tanks are sometimes placed in or on buildings, but great 
care should be taken to determine whether or not the building 
is sufficiently strong for the purpose. Water in quantity is 
very heavy: 300 gallons will weigh 2500 pounds, to which 
must be added the weight of the tank. Tanks placed in 
residences have often caused settling of the framework under- 
neath and consequent cracking of the plastering. In barns 
they can be supported to better advantage. 

Cement or concrete towers and tanks are coming into use 
and, when properly built and reinforced, there is no reason 
why they should not be economical. 

The masonry silo provides what is seemingly a good loca- 
tion for a water tank for a farm water supply. The tanks 
themselves may be built of masonry if properly reinforced, 
and plastered with cement plaster on the inside. The bottom 
of the tank can be easily constructed of concrete, if built in a 
conical form and reinforced to prevent cracking at the base. 

The Air-Pressure System. The pressure tank, or pneu- 
matic system, consists of an air-tight tank, a force pump, 




Pig. 305. An air pressure or pneumatic water supply system. 



FARM SANITATION 



495 



and suitable piping. As water is forced in at the bottom of 
this tank, the air within is compressed, thus driving the 
water from the tank to any part of the system. As the 
effective capacity of the tank may be increased by having 
an initial pressure of air within it, and as the water con- 
tinually absorbs a part of the air, an air pump or a pump 
to supply the air with the water must be provided. 

As the water is thoroughly protected by being tightly 
inclosed, the tank may be placed where a freezing tempera- 
ture is not reached. The cellar is the usual location. It 
may, however, be buried in the ground, which has the advan- 
tage that the water is kept at quite a uniform temperature 
throughout the entire year. 

The air pressure tank for a water supply of small capacity 
is very economical in first cost. Where the storage capacity is 
large, however, the cost is so great as to be almost prohibitive. 
A ten-barrel tank with a 
water storage capacity of 
six barrels will cost about 
$60, and larger tanks a 
correspondingly greater 
amount. 

A more recent water- 
supply system is known 
as the Perry pneumatic 
water-supply system. It 
consists in a power-driven 
air compressor, a storage 
tank for the air under 
pressure, and an air- 
driven water pump which 
pumps the water as required, maintaining a pressure upon 
the entire system. There is no storage of the water at all, 



Outer ce>.s//7. 
wifh screw ce>.p 



.r^s^:. T~7 




■Su pply Pipe 4. 
below frost lira 



Course 
Or£>vel 



A satisfactory method of install- 
ing exposed hydrants. 



496 AGRICULTURAL ENGINEERING 

other than that contained in the pipes. Definite information 
is not at hand concerning the cost or the success of this system. 
One distinct advantage of it is that water maybe pumped from 
as many supplies as there are pumps. Thus one pump may 
supply well water for drinking purposes, and another cistern 
water for the bath and laundry. 

QUESTIONS 

1. What kind of pipe may be used in the distribution system, and 
what are the merits of each? 

2. What are the sizes of pipe generally used for the farm water- 
supply system? 

3. Explain how the loss of friction may be serious with small pipes. 

4. Describe the ramified and circulatory systems of water piping. 

5. What provision may be made for fire protection, for repair, and 
or cool drinking water in the water supply system? 

6. In what way does the amount of water storage vary with the 
source of power? 

7. Describe the two general systems of storing water. 

8. Discuss the construction of elevated water supply tanks. 

9. What are the objections to an exposed water supply tank? 

10. What care should be taken when the supply tank is placed in 
a building? 

11. Why does a masonry silo make a good tower for a water supply 
tank? 

12. Describe the air pressure or pneumatic system of water supply. 

13. What are the advantages of this system and the main objection 
to it? 

14. Describe the Perry system. 

15. What is the principal advantage of this system? 



CHAPTER LXXVII 
PLUMBING FOR THE COUNTRY HOUSE 

Modern conveniences for the country home are usually 
understood to include sanitary plumbing fixtures for the 
bathroom and for caring for the wastes of the household. 
The use of such fixtures is dependent upon an adequate water 
supply, a subject which has been discussed in the preceding 
chapters. There is nothing which will do as much toward 
relieving the housewife of hard and disagreeable labor as the 
plumbing. It not only provides additional comfort and con- 
venience to the extent that when once used it is considered 
indispensable, but it also guards the health of all members 
of the household. 

Opinions differ widely in regard to the details of construc- 
tion and design of sanitary plumbing. In all cases care must 
be used that unnecessary expense is not incurred in securing 
something which does not represent quality. As a rule the 
most simple fixtures are the most satisfactory. All parts of 
the fixtures, such as traps and overflows, should be so placed 
as to permit of ready inspection. 

Plumbing Fixtures. In installing plumbing fixtures, con- 
solidation should be kept in mind. The usual fixtures 
installed in a country home are a sink and hot water appli- 
ances in the kitchen, and a bathtub, closet and lavatory in the 
bedroom. If the bathroom can be placed above or adjoining 
the kitchen the installation of the fixtures will be much sim- 
plified and much piping saved. The number of fixtures 
which may be installed will depend largely upon whether or 
not the house is to have furnace heat. If the house is to be 



498 



AGRICULTURAL ENGINEERING 



heated with stoves, the bathroom can best be arranged to 
adjoin the kitchen, and the heat therefrom ought to prevent 
the freezing of the water in the pipes. For this reason the 

pipes should be protected 
as far as possible from the 
cold. It is not best, how- 
ever, to place them in the 
wall, as exposed pipes are 
decidedly more convenient 
to repair. One very satis- 
factory method of caring 
for the pipes is to provide 
a conduit with a removable 
cover, which may be panel- 
ed in such a way as not to 
detract from the appear- 
ance of the room. All of 
the fixtures requiring 
drainage should be clus- 
tered about the soil pipe 
which should extend from 
the cellar up through the 
building and out through 
the roof for ventilation. 
This soil pipe is univer- 
sally made of four-inch 
cast-iron pipe with fittings 
inserted at proper places 
to receive the drainage 
from the various fixtures. 
It is best that a clean-out plug be provided at the bottom. 
At a slight additional cost, hot water may be provided. 
All that is required in addition is a hot water or range tank 




Fig. 307. A plumbing system for a 
two-story house. The vent pipe may be 
omitted with safety in country resi- 
dences. (Mo. Eng. Exp. Sta. Bui.) 



FARM SANITATION 499 

and a water front for the kitchen range or furnace, and the 
necessary piping. The range tank is galvanized and usually 
holds from 30 to 60 gallons. 

The kitchen sink is one of the fixtures which is well-nigh 
indispensable. The cast-iron sink, porcelain lined and with 
a roll rim and a back piece, is the most convenient for clean- 
ing. The porcelain-lined sink is just as serviceable, if not 
more so, than the solid porcelain, and is much cheaper. It is 
very difficult to keep a plain iron sink clean, and the advan- 
tages of the porcelain-lined will justify its purchase. 

A very satisfactory size for a kitchen sink is 22 by 36 
inches, and it should not be smaller than 20 by 30 inches. 
Though opinions differ, 32 inches is an average satisfactory 
height. One side may be conveniently arranged to receive 
the dishes as they are washed, permitting them to drain. 

Bathroom Fixtures. The bathroom ordinarily contains 
three fixtures; namely, a bathtub, a lavatory, and a water 
closet. Of recent years these fixtures have been greatly im- 
proved and cheapened in cost until a good grade is within the 
reach of all. A serviceable bathtub is one of cast iron, porce- 
lain lined but with a wide roll at the top. Like the kitchen 
sink it should not have any woodwork connected with it. 
The best tubs have all of the piping, including the drains and 
overflow, exposed. The standard width for bathtubs is 30 
inches, and they may be had in any length from 4 to 6 feet. 

The lavatory should be either solid porcelain or porcelain- 
enameled cast iron. To avoid cracks in which dirt may 
accumulate, the back should be made solid with the bowl. 

The water closet in general use is of solid white earthen- 
ware with siphon action. The cleaning jet should discharge 
from the rim of the closet and should clean thoroughly. Two 
kinds of flush tanks are in general use, the "low down" and 
the "high." The first does not make as much noise when 



500 AGRICULTURAL ENGINEERING 

flushed as the second but generally u?e? more water. The 
water is discharged from the second wlon considerable force, 
and for that reason is preferred by some. 

Back Vents. In nearly all cities all fixtures are required 
by law to have vents from the traps to prevent the water 
which closes the pipe and prevents the entrance of foul gases 
into the room from being siphoned over into the sewer. This 
system of piping is shown in the accompanying figure; it intro- 
duces considerable extra expense. In country houses there 
is doubtless little danger in omitting this extra piping. 

There will be little difficulty in installing plumbing in a 
house not built especially for the purpose, providing there is 
room for it. There is some inconvenience in putting the 
pipes in place, but in most cases they can be left in exposed 
locations, which is some advantage. 

The plumbing referred to and of the quality suggested 
will cost less than $200 almost anywhere in the Middle West; 
in fact, the average cost should not exceed $150. 

QUESTIONS 

1. What are some of the general considerations involved in the 
installation of plumbing? 

2. How may plumbing be arranged in houses without furnace heat? 

3. How secure convenience in cleaning and inspection? 

4. What are the usual fixtures required? 

5. Discuss the merits of various grades of sinks. 

6. What should be avoided in the selection of a lavatory? 

7. Discuss the different types of water closets. 

8. What is meant by back venting? 

9. How much should the plumbing in an average farmhouse cost? 



CHAPTER LXXVIII 
THE SEPTIC TANK FOR FARM SEWAGE DISPOSAL 

Modern plumbing fixtures for the farmhouse introduce a 
new problem, the disposal of the sewage. Present-day ideas 
concerning sanitation have made the privy and the cesspool 
less tolerable than formerly. The modern sewage disposal 
plant, if it is to fill its purpose to the greatest extent, should 
not only prevent accumulation of sewage to harbor disease 
and contaminate the water supply, but should also provide 
for the saving of fertilizing material which otherwise would 
be wasted. 

Disposal of Sewage into Rivers. If a large stream of 
water be near, the sewage may be discharged into it in a 
manner similar to that followed by the large cities. The 
organic material contained in the sewage when exposed to 
the light and air as it passes off down the river is rapidly 
purified by bacterial action. Rivers as a means of disposing 
of the sewage from farmhouses are rarely available and will 
not be discussed further. 

The Cesspool. While the cesspool has been the most 
common method of disposing of sewage in isolated places, it 
has but few features to commend it and should not be used if 
there is the least danger of its spreading disease. As usually 
constructed the cesspool consists of a cistern in the ground, 
with an open wall, usually of brick, through which seepage 
takes place. In some open soils this seepage is rapid, and no 
difficulty is experienced from the cesspool overflowing at 
times. In dense, retentive soils, the solid matter of the sew- 
age closes the porous walls to the extent that the liquids do 



502 AGRICULTURAL ENGINEERING 

not sweep away fast enough. If there is much grease in the 
sewage it is apt to become hardened over the surface of the 
walls, making them water-tight. To overcome this difficulty 
common lye has been used to cut the grease, with good success. 
All cesspools should be arranged with a manhole, which will 
permit the settlings or solid matter which collects in the 
bottom to be removed at regular intervals, perhaps once 
a year. 

Many cesspools that have been in use for years are entirely 
satisfactory as far as observations go. The success of these 
is undoubtedly due to the purifying bacterial action which 
the sewage undergoes in the tank. At best, however, the 
cesspool is a dangerous means of disposing of sewage, and 
new installations should be of more improved design. Often 
the contamination of the water supply is effected at an un- 
dreamed-of distance, resulting in typhoid fever, dysentery, 
and other complaints. 

Principles of Sewage Disposal. The principle involved 
in the purification of sewage in the modern disposal plant, 
regardless of whether it be for city or private use, is largely 
that of destroying the suspended matter in the water by 
bacterial action. Outside of this, some results are brought 
about by settling, thus caring for a part of the suspended 
material. 

When the sewage from a farmhouse, consisting of the wash 
water from kitchen and dairy and the discharge from plumb- 
ing fixtures, is drained into a dark reservoir and not disturbed 
for a time, rapid bacterial action takes place. The bacteria 
which work in a tank of this sort do not need light or air to 
live. The action is simply this: the bacteria feed upon the 
organic matter of the sewage and thereby partially destroy it; 
in addition, a partof this solid matter, or sludge, as it is called, 
is liquified. 



FARM SANITATION 



503 



The reservoir provided for this purification by bacterial 
action is known as the septic tank. To secure the best 
results, this septic tank should be designed to exclude light 
and air and to bring the sewage to rest and hold it so for a 
time. 

The purification of the sewage, however, is not completed 
in the septic tank. To complete the process, means must 
be provided to permit another class of bacteria to act upon 



Ouf/ef 




Fig. 



30S. A general view of a septic tank arranged to be connected with 
an underground irrigation or filter system without a siphon. 
(After Stewart.) 



the sewage. These must have air and light or they cannot 
live. To supply the proper conditions for this second bac- 
terial action, two plans are followed : the first is to provide a 
filter bed of coarse material, usually gravel, over which the 
sewage from the septic tank is discharged at intervals; and 
the second is to provide a shallow tile system from which per- 
colation will take place. These tile are usually placed within 
ten to twelve inches of the surface, and, if the soil is retentive, 
a second and deeper system is laid to carry away the purified 
sewage. In some places this filter system of drain tile is used 



504 



AGRICULTURAL ENGINEERING 



as a means of subirrigation, furnishing the growing plants on 
the surface with moisture and fertility. It is to be noted that 
the discharge into the filter system should be intermittent, in 
order that the bacteria at work shall not be drowned. 

Another plan of filtering which is used to some extent is 
to allow the discharge to trickle down through a bed of sand, 
which is placed over a perforated cover, to a second tank in 
which the water level is maintained several inches below. 
The dripping of the sewage through the air corresponds quite 




Fig. 



•SecS/osr on A3 

309. Section of a septic tank made entirely of concrete. 
a siphon and a filter bed of sand and gravel. 



closely to the sprinkling system of sewage disposal which is 
used to some extent in city plants. 

Size of Septic Tank. The septic tank should be suffi- 
ciently large to hold the entire discharge for about one day, 
in which case the best bacterial action will be obtained. 
Another rule tried out more or less by practice is to provide 20 
gallons' capacity for each person in the household. There will 
be a settlement amounting to several pailfuls in the septic 
tank each year, and provision must be made for its removal. 

Construction of the Septic Tank. Concrete is the best 
material for the septic tank. The tile line to the tank from 
the house should be of vitrified bell-mouthed tile with 
cemented joints. 



FARM SANITATION 



505 



Fig. 308 is a general view of a septic tank which has been 
built for as little as $18.65. It has a plank top, and the only 
means of cleaning it out would be to uncover the earth and 
remove the planks. Fig. 
309 is a more expensive 
plant, with a filter bed 
attached. The filter bed 
complete will cost by it- 
self about $20. The best 
results can be secured 
with a tank provided with 
a siphon. Fig. 310 shows 
a plan for laying the tile 
system to filter the discharge from the septic tank. 

It is remarkable how thoroughly sewage can be purified by 
an efficient plant. Often the effluent or final discharge from 
the filter bed will compare in purity with the best well water. 




Fig. 310. A plan of 
filtering the discharge 
tank. 



tile system foi 
from a septic 



QUESTIONS 

1. How is sewage purified that is discharged into a river? 

2. What are the objections to a cesspool as a means of disposing 
of sewage? 

3. Discuss the construction of the cesspool. 

4. How is sewage purified in a septic tank? 

5. How can complete purification of the sewage be obtained? 

6. Why is it best to have the sewage applied intermittently to the 
filter bed or irrigation tile? 

7. Discuss the construction of the septic tank. 

8. Estimate the cost of a sewage disposal plant for a household of 
ten people. 



CHAPTER LXXIX 
THE NATURAL LIGHTING OF FARM BUILDINGS 

Development. If a comparison be made between the 
farm buildings of twenty-five years ago and those which are 
entitled to be called modern, it would be found that one of the 
principal differences lies in the natural lighting, or the amount 
of window surface provided. This change is due largely to a 
more general recognition of the value of light as a sanitary 
agent. 

Purpose of Natural Lighting. The natural lighting of 
farm buildings has a three-fold purpose: (1) The principal 
purpose, to make the buildings more sanitary by destroying 
disease germs; (2) to provide a more convenient and pleasant 
place for the attendants to care for the animals; and (3) to 
provide more pleasant and comfortable quarters for the 
animals to feed and live in. As stated, the principal reason 
for providing adequate natural light for farm buildings is to 
secure sanitary quarters for the animals. Direct sunlight is 
far more powerful and destructive to disease germs than 
diffused or reflected light, and for this reason as much direct 
sunlight as possible should be provided. Usually but a short 
time, a few hours, is required to kill germs by direct sunlight. 

In regard to the value of diffuse light for destroying 
germs, Dr. Weinzirl, an eminent bacteriologist, is quoted in 
King's book on Ventilation as follows: "The shortest time 
in which diffuse light in a room killed the bacillus of tuber- 
culosis was less than a day, and the longest time was less than 
a week; generally, three or four days of exposure killed the or- 
ganisms. Some pus-producing bacteria required a week's 



FARM SANITATION 



507 



time to kill them, while some intestinal bacteria were killed 
in a few hours. It was also found that bacteria are killed 
more quickly in moist air than in dry, contrary to general 
belief. The diffuse light as found in our dwellings is, there- 
fore, a hygienic factor of great importance, and where direct 
sunlight is not available it should be carefully provided for." 
It is believed that the above quotation represents a clear, 
authoritative statement of the value of diffuse sunlight in 
producing sanitary quarters. 

Location of Windows. In locating the windows, great 
care should be taken that sun- 
light will be admitted in such 
a way as to allow the direct 
beams of light to sweep the 
entire floor. The angle of 
incidence of the sun's rays, or 
the distance of the sun above 
the horizon, for latitude 42° 
north varies from 70° the 22nd 
of June to 26° the 21st of Dec- 
ember. For other latitudes 
the angle of incidence is 
different. At the spring and 
fall equinoxes, which take 
place March 21 and Sept- 
ember 21, and for 42° N. the 
angle is 48°. Sunlight is more 
useful in the winter time than 
in the summer, and care 

should be taken to make use of the winter sun rather than the 
summer sun. For practical purposes it can be assumed that 
the most desirable sunlight enters the windows at an angle 
of 45°. 




Fig. 311. A sketch showing how 
the angle of incidence of the sun's 
rays varies throughout the year. This 
is at latitude 42° N. 



508 



AGRICULTURAL ENGINEERING 




Fij 



Design of Windows. The window casings should be 
designed to intercept as little of the direct sunlight as possible. 
Stone or concrete walls of considerable thickness should be 
^ beveled on the inside so 

as to let in the full width 
of the beam of sunshine 
passing through the 
glass. For this reason 
windows that are long 
vertically are more de- 
sirable and more effi- 
cient than those which 
are wide but low. In 
the latter instance the 
casings and wall cut off 
a large proportionof the 
direct light admitted. 
Again, wide, over-hang- 
ing eaves cut off much 
direct sunshine from the windows located directly below. 

Size of Windows. No definite rules can be given for the 
amount of window surface to provide in barns and other farm 
buildings, owing to the fact that the efficiency of the windows 
depends so much on their location. It is good practice, how- 
ever, to provide one square foot of glass for every 20 to 25 
square feet of floor surface. Judgment must be used in this 
connection, varying the amount with the location and shape 
of the windows. Dairy barns are generally provided with a 
larger window area than horse barns. 

There is a tendency to go to the extreme in lighting dairy 
barns. Many barns have been built during recent years with 
entirely too much window surface. Such buildings are too 
cold when located in the northern climates, at least. Ade- 



312. A sketch showing the effect 
of thick walls upon the amount of direct 
sunlight admitted, the greater efficiency 
of deep windows over shallow windows, 
and also the effect of over-hanging eaves. 



FARM SANITATION 509 

quate window surface does not add materially to the cost of 
the construction and should not be admitted for this reason. 
Wide buildings and basement barns cannot be lighted well, 
and for this reason should be guarded against. It is to be 
remembered in this connection that natural lighting is only- 
one factor in providing sanitary quarters. Cleanliness and 
ventilation are more important; but none of these features 
should be neglected. 

QUESTIONS 

1. Describe the changes which have taken place in the natural 
lighting of farm buildings. 

2. What is the threefold purpose of the natural lighting of farm 
ouildings? 

3. What value has direct sunlight in destroying disease germs? 

4. Discuss how windows should be located to be the most effective. 

5. What should be the general shape of windows, and what may- 
be said concerning the thickness of casings and width of eaves? 

6. Discuss the relation between window surface and floor surface 
in different types of buildings. 



CHAPTER LXXX 
LIGHTING THE COUNTRY HOME 

Development. It is extremely interesting to study the 
development of the art of lighting, or illumination; yet it is 
not the function of this chapter to discuss this phase of the 
subject. Our fathers and mothers were compelled while 
young to depend on the tallow candle, the tallow dip, or 
the light of the fire in the fireplace. History relates how 
many of our famous men of the past century spent hours 
in the nickering light from the "back log" poring over a book 
which they were endeavoring to master. The petroleum 
industry was not developed until 1860, and the general 
use of kerosene in lamps did not come until many years 
after this. The kerosene lamp, when provided with a 
chimney to control the draft and produce more perfect com- 
bustion, was a great improvement over the ill-smelling 
and smoking tallow candle or dip. 

The various sources of light for rural conditions are the 
kerosene lamp, the gasoline lamp or system, the acetylene lamp 
or system, and the electric lighting plant. Alcohol might be 
burned in lamps, but at its present cost cannot compete with the 
petroleum oils. These various systems will be discussed in turn. 

The Unit of Light — The Standard Candle. In comparing 
lamps it is necessary to refer to the unit of illumination, the 
standard candle by which all lamps are rated. The standard 
candle for the United States and Great Britain is the sperm 
candle seven-eighths of an inch in diameter and burning 120 
grains of sperm per hour. This standard is not very satisfac- 
tory, as it tends to vary. The International Unit of Light 



FARM SANITATION 511 

was adopted by the United States July 1, 1909, and is now the 
legal unit of light, and is practically equal to the standard 
candle. 

The art of measuring the illumination of any source of 
light is called photometry. The principle involved consists 
in placing the source of light, or the lamp to be measured and 
a standard lamp whose candle power is known, at such dis- 
tances from a screen that the intensity of the light from each 
is equal. As the light from a lamp passes out in all directions, 
it is to be expected that the intensity of the light at all points 
on the surface of a sphere at a certain radius from the source 
will be equal. As the surfaces of spheres vary as the square 
of their radii, the intensity of light varies inversely as the 
square of the distance from the source. This assumes that 
the source of light is a sphere, which is not true. 

Kerosene Lamps. Kerosene lamps are still in common 
use, and, although they have some very serious objections, 
their merits should not be entirely overlooked. In the first 
place kerosene lamps are cheap as far as first cost is con- 
cerned. The fuel is cheap and can be obtained almost any- 
where. Kerosene lamps are quite safe; in fact, they excel 
many others in this respect. There- is more danger in the 
matches than in the lamps themselves. The lamps are 
readily portable, which is not true of all sources of artificial 
light. 

On the other hand there are many disadvantages. The 
odor of kerosene lamps is not pleasant, although far more 
offensive to some persons than to others. Kerosene lamps 
require attention in the way of trimming the wicks and clean- 
ing the chimneys. If a large number of lamps are to be 
cared for, the time required daily is considerable. Much 
heat is developed by a kerosene light, which at times may 
be a serious disadvantage. The lamp also consumes a large 



512 



AGRICULTURAL ENGINEERING 




amount of oxygen and necessitates more rapid ventilation. 

A large lamp will consume more oxygen than several persons. 

There is more or less smoke com- 
ing from the flame, which settles 
as soot upon the furniture and 
walls of the room. 

The light from a kerosene lamp 
is a yellowish orange. It is not 
white enough to be a perfect light. 
Authorities differ in regard to the 
effect of the light from a kerosene 
lamp upon the eye, but it is gen- 
erally regarded as a quite suit- 
able light. The addition of a 
mantle, which is a net of rare 
earths, to a kerosene lamp to in- 
close the flame, increases the 
efficiency many fold. This will 
be shown definitely in the data 
from tests which will follow. 
Mantles, however, are very fra- 
gile and increase the cost of keep- 
ing the lamp in service. The 
average kerosene lamp furnishes 
light at the rate of 15 to 30 candle 
power. 

It is to be noted from the 
table that the mantle has a de- 
cided effect upon the efficiency 
of lamps, raising the candle- 
power-hours per gallon from 600 

Fig. 313. A good type of ker- , nr\r\r\ /"< v l 

osene lamp. The efficiency of to over 3000. Gasoline lamps are 
tne%^fr u manu e e. d ° ubled by in reality gas lamps, for they 




FARM SANITATION 



513 



must convert the liquid into gas before it is burned. Gaso- 
line lamps are either portable, with an individual generator, 
or are connected to a system, with a common generator for the 
entire system. Again, certain gasoline plants require a 
special grade of light gasoline which is vaporized upon mixing 
with air. 

Gasoline Lamps. Gasoline lamps are not as safe as kero- 
sene lamps, yet when properly handled should not be danger- 

The efficiency of lamps. 













Cost per 








Candle 


Candle- 


eandle- 


Kind of lamp 


Size 


Where tested 


power 


power-hrs. 
per gal. 


power-hr. 
Kerosene 
at lie. 


B. &H. Burner. 


\ x /l in. dia. 


la. Exp. Sta. 


33.5 


877 


.0125c 


Common flat wick 


XYi in. wide 


Pa. Exp. Sta. 


11.66 


591 to 


.017c 








12.91 


789 


.017c 


Rochester. 


\ x /i in. dia. 


Pa. Exp. Sta. 


16.02 
19.04 


350 to 
538 


.023c 


Saronia with Ar- 












gand burner and 












mantle 


% in. dia. 


Pa. Exp. Sta. 


27.46 
30.26 


1312 to 
1515 


.008c 


Chancester with 












Argand burner 












mantle 




Pa. Exp. Sta. 


30.6 
32.4 


3134 to 

3402 


.0034c 



ous. They should be filled only by daylight, and care should 
be taken not to let the gasoline become exposed to the air 
either through a leak or by spilling. A gasoline lamp, unless 
of the vaporizing type, requires some time for starting, and 
must be heated before the gasoline can be generated. While 
it is burning, there is usually a hissing noise which is very 
disagreeable. Gasoline lamps are universally mantle lamps, 
and for this reason are very efficient. The most efficient 
lamps are those which furnish the liquid to the lamps under 
pressure. The gasoline lamp consumes the oxygen of the 
air and heats it much as the kerosene lamp. 



514 



AGRICULTURAL ENGINEERING 

Efficiency of gasoline lamps. 



Kind of lamp 


Where tested 


Candle 
power 


Candle- 

power-hrs. 

per gal. 


Cost per can- 
dle-power- 
hour at 20c. 


Bracket lamp 
Hanging lamp 
Pressure lamp at 34 lbs. 

Underneath generator 


la. Exp. Sta. 
la. Exp. Sta. 
la. Exp. Sta. 

Pa. Exp. Sta. 


51.2 

65.5 

300.0 

36 to 46 


2948 
3180 
4550 

1885 


.0068c 
.0063c 
.0043c 

.0120c 




. 314. A gasoline lamp. The tubini 
coiled so as to appear in the pic- 
ture. 



QUESTIONS 

1. What are the improved 
systems of lighting? 

2. How were houses light- 
ed by artificial means in early 
times? 

3. What is the common 
unit of light, and explain how 
it is established? 

4. Explain how the illumi- 
nation of any source may be 
measured. 

5. What are the advan- 
tages and disadvantages of 
kerosene lamps? 

6. What effect does the 
use of a mantle have upon 
the efficiency of lamps? 

7. Discuss the merits of 
gasoline lamps. 

8. How does the cost of 
light from kerosene, alcohol, 
and gasoline lamps compare? 

9. Estimate the cost of 
lighting the average farm- 
house during a period of one 
year with the different 
systems. 



CHAPTER LXXXI 
THE ACETYLENE LIGHTING PLANT 

The Principle of the Acetylene Plant. When a lighting 
system for the farm is desired which will furnish the equal of 
city service, the acetylene plant is one of the first to receive 
consideration. Acetylene gas is made by bringing calcium 
carbide in contact with water. In portable lamps the water 
is allowed to drip upon the carbide ; but with larger plants, the 
carbide is fed into a rather large tank of water mainly to keep 
the temperature of the gas as low as possible. The heating 
of carbide and water is like that of unslaked lime and water, 
and the resulting residue is the same — nothing more or less 
than common whitewash. 

Calcium Carbide.' The calcium carbide is made by sub- 
jecting a mixture of coke and lime to the intense heat of the 
electric furnace. The resulting product is of dark-gray color 
with a slightly crystalline structure. The carbide industry 
is practically monopolized in this country by the Union Car- 
bide Sales Company, from which all purchases must be made. 
Distributing depots are located at various points throughout 
the United States, there being one in each state, or perhaps 
more in some instances. The cost of carbide at these depots 
at the present time is $3.75 per hundred pounds. It is shipped 
in metal cans as third-class freight. The carbide is no more 
dangerous than unslaked lime; the only precaution necessary 
is to keep it free from moisture. There are four sizes of car- 
bide carried regularly in stock; viz., Lump, Egg, Nut, and 
Quarter. The last two sizes, Nut Y± inch by % inch, and 
Quarter, 34 mcn by 1/ 12 inch, are the two commonly used in 
carbide feed generators. 



516 



AGRICULTURAL ENGINEERING 



Acetylene Gas. Acetylene is a colorless, tasteless gas 
composed entirely of carbon and hydrogen. It is lighter than 
air, but much heavier than coal gas. Acetylene burns with 
a very white light, almost like sunlight. It is easy on the eyes 




Fig. 315. A 35-Iight acetylene generator. 



and enables one to distinguish colors accurately. The com- 
bustion of acetylene deprives the air of about 23^> cubic feet 
of oxygen for each cubic foot burned. The flame, for equal 
candle power, produces less heat than the kerosene lamp. 



FARM SANITATION 



517 



Being a rich gas, acetylene will form a dangerously explo- 
sive mixture with air; yet an explosive mixture, which must 
contain between ^ to 25 times as much air as gas, is so 
unlikely to occur, on account of the ease by which gas leaks 
are detected, that accidents are seldom heard of. 

Acetylene gas will cause asphyxiation, yet not nearly so 
readily as coal gas, which is used for illumination in the cities. 
No fatal results from inhalation are on record, and it is 
claimed that death could not occur until the gas was present 
in the proportion of at least 20 per cent. 

Production of Acetylene Gas. When calcium carbide is 
mixed with water, each pound should, if the carbide is chem- 
ically pure, yield 5}4 cubic feet of gas. This gas is very rich, 
containing about 1700 British thermal units per cubic foot, 
nearly three times that of 
coal gas. The commer- 
cial carbide yields from 
434 to 53^ cubic feet, de- 
pending somewhat upon 
its purity, the moisture 
absorbed, and the amount 
of dust present. Theo- 
retically, .562 pounds of 
water will be needed for 
each pound of carbide, 
but in practice as much 
as eight pounds are sup- 
plied. The most com- 
mon size of burner used 
consumes 3^ cubic foot of 
gas per hour, and gives a 
25-candle-power light. Other standard sizes are the 1, %, 
and M cubic foot burners. These burners are all forked in 




Fig. 316. A section of the generator 
shown in Fig. 315. A is the motor or 
clockwork for operating the carbide feed, 
B is the carbide feed, C is the weight for 
running the motor, D is the carbide bin, 
E is the agitator in the water tank for 
storing up the residue before cleaning, 
F is the gas holder, G is the gas filter, 
and H is the pipe line to supply lamps. 



518 AGRICULTURAL ENGINEERING 

such a way that two jets of flame are directed toward each 
other, forming a fan-shaped flame. 

Mantles are not used with acetylene burners, owing to 
the fact that it is almost impossible to light the gas without a 
slight explosion or jar which would destroy the mantle. If 
mantles could be used they would raise the efficiency of the 
lamps many fold. 

Cost of Light. If it is assumed that one pound of carbi de, 
costing $4 per hundredweight, will furnish five cubic feet of 
gas, and that a burner using one-half cubic foot per hour will 
furnish a 25-candle-power light, it is easy to calculate the cost 
of acetylene light per candle-power-hour for comparison with 
other lighting systems . Thus if }4 cubi c foot of gas costs 4/10 
cent, which is the cost of 25 candle-power-hours of light, one 
candle-power-hour will cost 1/25 of 4/10 cent or .016 cent. 

In a test of a portable lamp, made at the Pennsylvania 
agricultural experiment station, from 127 to 140 candle- 
power-hours were obtained from a pound of carbide, costing 
5 9/10 cents per pound. This would make the cost of light 
per candle-power -hour .043 cent. 

Essentials of a Good Acetylene Generator. All acetylene 
light plants must have a generator whose function is to feed 
the carbide to the water, or the water to the carbide, which 
is less usual, as the gas is used. The essentials of a good 
acetylene generator may be summarized as follows: 

1. There should be no possibility of the existence of an 
explosive mixture in the generator at any time. The National 
Board of Fire Underwriters has prepared a list of generators 
which have passed inspection; and each buyer should see that 
the makeof machine purchased has been inspected and listed. 

2. The generator must insure cool generation. 

3. The construction must be tight and heavy enough to 
resist rapid deterioration. 



FARM SANITATION 519 

4. It should be simple in construction so as to be readily 
understood and not likely to get out of order. 

5. It should be capable of being recleaned and recharged 
without loss of gas into the room. 

6. There should be a suitable indicator to show how 
much carbide remains unused. 

7. The carbide should be completely used up, generating 
the maximum amount of gas. 

Size and Cost of Plant. Generators are made in various 
sizes, the rating being based upon the number of 3^-foot 
lights that can be supplied with gas. The sizes vary from 
20-light to 1000-light, but 25, 30, and 35 are the usual sizes. 
The list prices of these are 120, 135, and 150 dollars, respec- 
tively. In addition to the cost of the generator, the cost of 
the piping, fixtures, and installation must be added. For an 
eight-room house, the total cost will be about as follows : 

Generator $150 

Piping system 40 

Drain and foundation for generator 10 

Fixtures, eight rooms and basement 40 

Barn additional . . 15 

Total $225 

It is to be understood that this estimate cannot be made 
very definite owing to the varying number of fixtures required 
and the cost of labor, freight, etc. 

QUESTIONS 

1. How is acetylene gas made? How is carbide made? 

2. Discuss the cost and sizes of carbide. 

3. Describe the characteristics of acetylene gas. 

4. Discuss the cost of light from acetylene gas. 

5. What are the essentials of a good generator? 

6. Itemize the cost of an acetylene plant. 

7. What care should be used in installing an acetylene system? 



CHAPTER LXXXII 
THE ELECTRIC LIGHTING PLANT 

Development. Two great improvements have recently 
been brought about which have done much to make the 
private electric plant far more successful than ever before. 
In the first place, the new tungsten incandescent lamp has 
practically reduced the consumption of electricity per candle- 
power-hour to about one-third the former rate. In the second 
place, there have been some very decided improvements 
in storage battery construction, not only making them more 
reliable, but cheaper. 

Electric Light. Illuminating engineers agree that the 
incandescent electric light is the nearest approach to the ideal 
light that is now to be obtained. Its first great merit lies in 
its convenience. It is only necessary to turn a button or 
switch and the light is on or off as desired. It is the cleanest 
of all lights, no dust, no soot, and no odor. Furthermore, the 
electric light does not vitiate the air by consuming the oxygen. 
Of all lights it is by far the safest and may be taken directly 
into places filled with combustibles. 

The serious objection to the electric light which has been 
raised in the past is its cost. The new tungsten lamp has 
done much to remove this objection, where it can be used, 
although it is rather fragile and cannot be used where the 
lamp is subject to shocks or sharp vibrations. Further, the 
cost of electric light may be somewhat overlooked on account 
of the advantages enumerated. The first cost of installing an 
electric plant is large, but not so much greater than the cost 
of installing an acetylene or gasoline plant. In addition to 



FARM SANITATION 



521 



lighting, the electric current may be used for other purposes- 
small motors, electric irons, etc. 

The Electric Plant. It does not seem practical to install 
an electric plant large enough to furnish power to the various 
machines used on the farm. Not only would the cost of in- 
stallation be very great, but such a plant when used for light- 
ing would be very inefficient. An electric lighting plant 
consists primarily of a source of power or a motor of some sort, 
a generator or dynamo to furnish 
the current, the wiring, the lights, 
and, under all normal conditions, 
a storage battery to supply cur- 
rent when the motor and gen- 
erator are not running. 

The Source of Power. Water- 
power makes an ideal power for 
the plant, as it is almost always 
very cheap. It is, however, not 
often available ; hence the princi- 
pal source of power for the farm 
electric plant is the gasoline or kerosene engine. These, as 
has been shown, have developed to the point where they are 
quite reliable, and the power is furnished in small units at 
a very reasonable cost. Furthermore, the gasoline engine 
requires the minimum of attention while running, which 
is an essential feature of the entire private electric plant. 
Definitions. In discussing an electric plant, recourse 
must be made to some electrical terms. Electric current has 
two properties: (1) The pressure or the voltage, which is the 
measure of the tendency on the part of an electric current to 
flow; and (2) the amount of current flowing, or the amperage. 
Thus a 110- volt lamp requires 110 volts of pressure or voltage 
to make its filament glow brightly. If the lamp be a 16- 
candle-power carbon filament lamp only one-half ampere will 




s the common 
carbon filament electric lamp; B 
is the new tungsten lamp, which 
is much more efficient. 



522 AGRICULTURAL ENGINEERING 

pass through the lamp. The product of the volts by the 
amperes gives the electric power in watts, the watt being the 
unit of power. Thus for the lamp just referred to, the current 
consumption would be 1 10 x^, or 55 watts. One horsepower 
is equal to 746 watts. The output of dynamos or generators 
is rated in kilowatts, or units of 1000 watts. Electricity is 
purchased by the kilowatt-hour, which is electric current at 
the rate of one kilowatt continued for one hour. One kilo- 
watt equals 1.34 horsepower; thus to drive a one-kilowatt 
dynamo, a V/r or 2-horsepower engine is provided, as some 
power is lost in the friction of the dynamo itself. 

Selection of the Plant. In deciding upon a plant one of 
the first questions that arises is the matter of the voltage at 
which the plant is to be operated. Electric light plants are 
now made to furnish current at 25 to 110 or even higher 
voltage. The common voltages are 25, 60, and 110. The 
lower voltages have some advantages; viz., (1) first cost of 
the storage battery is lower; (2) the battery has fewer parts; 
(3) it can be used better with low candle-power lamps; 
and (4) the lamps, having shorter filaments, are stronger. 

The disadvantage of a low voltage lies primarily in the 
fact that it is not standard with any lighting plants and is 
inconvenient to procure lamps and other fixtures for it. 
There is a decided saving with high voltage, however, in 
connection with the wiring, especially if the current is to be 
transmitted far, since the size of wire required to furnish a 
given light with electricity varies inversely with the voltage. 
In other words, a wire will transmit twice as much electricity 
through a given size at 110 volts as at 55 volts. 

If the maximum number of 25-watt lamps in service at 
one time does not exceed 20, or the demands upon the dynamo 
from miscellaneous sources such as motors, flat iron, etc., 
does not exceed 500 watts, a one-half kilowatt generator 
may be used. A one-horsepower gasoline engine will furnish 



FARM SANITATION 



523 



the power unless required to do other work while running the 
generator. If pumping, churning, and other forms of light 
work are contemplated, a two-horsepower engine will usually 
be found very satisfactory. The storage battery must con- 
tain 56 cells, and if they are of the 20-ampere-hour size they 
will furnish all of the lamps with current for four hours. 




Engine, dynamo, storage battery, and switchboard of an elec- 
tric lighting plant. 



The Cost of the Plant. The total cost of plant may be 
estimated as follows: 

1 2-horsepower gasoline engine $125 

1 J^-kilowatt generator 60 

1 storage battery, 20-ampere-hour, 56 cells at $2.50 140 

1 complete switchboard 75 

17 tungsten lamps 17 

12 carbon lamps 3 

Wiring 50 

Fixtures 30 

Total cost $498 

The Cost of Light. The cost of operating the plant will 
be principally that of gasoline, which, at the usual price, will 



524 AGRICULTURAL ENGINEERING 

be between 1% and 2 cents per hour. Twenty 25-watt lamps 
will furnish 400 candle-power. Thus the cost per candle- 
power-hour might be at a minimum .00375 to .005 cents. As 
the plant will seldom be operated at full capacity, the aver- 
age cost will be much greater, perhaps double. 

Operation. The electric plant is not difficult to operate 
by one who has some knowledge of electrical machinery. 
The engine and the dynamo will not require a great amount of 
attention. The storage must be supplied with electrolyte 
from time to time. The battery is also the least durable part 
of the entire plant. Perhaps a new set of electrodes for the 
battery will be needed at the end of five years. A good engine 
ought to last at least ten years. 

QUESTIONS 

1. What improvements have made the electric lighting plants 
practical for farm homes? 

2. What are the advantages of electric light? 

3. Discuss the most serious objections to electric light. 

4. Is it generally practical to install an electric lighting plant large 
enough for power service? 

5. Discuss the various sources of power for electric lighting plants. 

6. Define voltage. Amperage. 

7. What is a watt? A kilowatt? 

8. What is the relation between watts and candle power with tung- 
sten lamps? 

9. What are the advantages of a low-voltage system? 

10. What are its disadvantages? 

11. Itemize the cost of an electric lighting plant. 

12. Discuss the cost of electric light. 

13. Discuss the care and maintenance of an electric lighting plant. 



CHAPTER LXXXIII 
HEATING THE COUNTRY HOME 

Systems of Heating. There are four systems of heating 
farm houses in use : 

1. By stoves. 

2. By a hot-air furnace. 

3. By a hot-water furnace and radiators. 

4. By a steam furnace and radiators. 

Stoves. The first of these is in common use, and perhaps 
little can be written here which will add to the general infor- 
mation upon the subject. The stove was invented to burn 
coal shortly after coal was discovered, for the fireplaces of 
the time were not adapted to the purpose. As usually 
designed the stove is not an efficient device, as perhaps 50 
per cent of the heat is lost up the chimney. It has other 
more serious shortcomings, however. In the first place the 
stove d ">es not produce a uniform temperature, owing to the 
fact that the air circulation within the room is not perfect. 
The success of any heating system depends primarily upon 
perfect circulation of the air. Air near the hot stove expands 
upon heating, becomes lighter and rises to the ceiling, and 
colder air takes its place. As the warmest part of the stove 
is several feet from the floor, the upper part of the room is 
usually much warmer than the lower. The inconvenience of 
handling and storing the fuel in the room, and the dirt, 
smoke and gases that are apt to result are also objectionable. 

If several rooms are to be heated, the management of the 
stoves becomes a troublesome matter. Almost any kind of 
fuel may be used in a stove, which is an advantage decidedly 



526 AGRICULTURAL ENGINEERING 

in its favor. Although coal requires less labor, wood is a 
clean and very desirable fuel. In certain sections of the 
country the fuel used is mainly corn cobs and other trash, and 
the stoves used are the so-called air-tight stoves which have 
a large magazine into which a bushel or more fuel may be 
placed at one time. This magazine obviates the necessity of 
feeding the fuel at short intervals. There is, however, some 
danger from the explosion of the gas which is generated from 
fresh fuel before the flames start. The heat of the smoulder- 
ing fire upon which fresh fuel is placed drives off certain 
combustible gases, which are ignited as soon as a flame 
starts up. 

By far the most satisfactory stove for the cold winters of 
the North is the hard-coal burner. When of sufficient size 
and well designed, with a good large magazine, the hard-coal 
burner may be used to heat several rooms to a comfortable 
temperature. The high cost of hard or anthracite coal in 
certain sections of the country renders the use of such a heater 
quite expensive. 

Radiators. In houses equipped with stoves an upper 
room can be comfortably heated by extending the stove pipe 
into the room and providing a radiator. This plan is highly 
commendable, as there is no additional expense connected 
with its use other than the cost of the radiator, which should 
not exceed $8, the value of a good one. 

Warm-Air Furnaces. Heating houses by means of warm- 
air furnaces does not differ materially from the use of stoves. 
The furnace is simply a large stove placed in the basement, 
with pipes to convey the heated air to the various rooms 
above. By placing the furnace in the basement many of the 
objections to the stove are overcome. First, the dirt con- 
nected with the firing and cleaning is kept where it is least 
objectionable. Proper circulation of the air may be secured 



FARM SANITATION 



527 



by arranging the pipes so that the temperature may be kept 
uniform in all parts of the house. 

The warm-air furnace has an advantage in that a house 
may be heated up quickly, and likewise the disadvantage that 
the house will cool quickly when the fire goes down, owing to 
the fact that there is no storage of heat. The hot-air furnace 
is very bad about conducting dust and smoke into the rooms. 
Often cheesecloth strainers are provided in the fresh air out- 
lets to keep out the dust. The average life of a hot-air 
furnace will not exceed 8 to 10 
years, and when it becomes old the 
plates are quite apt to be cracked 
or warped in such a way that 
there is a serious leakage of smoke 
and gas into the rooms. It is to 
be noted in this connection that 
the furnace is so large that it must 
be built in sections, and seams 
cannot be avoided. As air does 
not have the property of absorbing 
a large amount of heat quickly, 
the plates and castings are easily 
overheated. 

In strong winds the circulation of the air in the flues is 
seriously interfered with. Often there is a corner room more 
exposed than the others that cannot be heated with the hot- 
air system. 

Installation. In planning a house in which the warm-air 
system is to be used, thought should be taken to give the fur- 
nace a central location, that there shall be no long horizontal 
air pipes through which it will be difficult to start a draft. 
The size of the hot-air furnace is usually designated by the 
diameter of the fire pot, which ranges from 20 to 30 inches 




A typical warm-air 
furnace. 



528 



AGRICULTURAL ENGINEERING 



and over. The hot-air system of heating is much less expen- 
sive, as far as cost of installation is concerned, than the hot- 
water or steam system. 
The cost of a first-class 
furnace with double pip- 
ing to protect the wood- 
work from becoming 
over-heated, in a house 
of six rooms, ought not 
to exceed $200. 

The Hot-Water Sys- 
tem. The hot-water fur- 
nace with suitable radi- 
ators represents the most 
perfect system of house 
heating, but it is the 
most expensive of all and 
is slightly more difficult 
to regulate. Water is 
heated by the furnace, 
and the consequent ex- 
pansion and reduction in 
weight cause it to flow 
to the radiators above, 
where it becomes cooled 
and consequently heav- 
ier, causing it to flow 
downward to be heated 

Fig. 320. A hot-water heating system, again. An expansion 

The locomotive type of furnace or boiler, -j 1 U 

although not in general use, is said to be tank IS provided aDOVe 

quite satisfactory. ^ ^ ^^g fo &c _ 

commodate the extra volume of the heated water. The 
success of the hot- water system consists in providing a fur- 




FARM SANITATION 529 

nace, piping, and radiators of sufficient size. The capacity of 
a furnace depends primarily upon its heating surface, al- 
though the size is commonly designated by the size of the 
fire pot. 

Radiators. Radiators, designed to give off heat from the 
water heated in the furnace, are made of cast iron, pressed 
steel, or pipe. In any case the amount of heat furnished is 
determined by the amount of surface from which the heat 
may radiate. This is always measured in square feet, and 
one feature of the design of a hot-water system is to provide a 
sufficient amount of radiating surface to heat each room. 
Radiators may be obtained with greater or less number of 
sections in various sizes, to furnish any amount of radiating 
surface desired. 

Estimating the Radiation. One rule for determining the 
amount of radiation for climates where the temperature occa- 
sionally falls below zero is as follows : 

cubical contents of room 

Square feet of radiation = — — — ■ — — ■ ■ — ■ -(- 

200 
square feet of glass 

+ lineal feet of exposed wall. 

2 

The hot-water system will successfully heat rooms on the 
side of the house exposed to strong wind. It is much cleaner 
and the plant will last at least twice as long as the hot-air 
system. The cost will, however, be from one-half to double 
that of the hot-air system. It is claimed that the hot-water 
system uses one-third less fuel than the hot-air furnace. 

A steam system may be installed for heating residences, 
but it requires close attention and so is seldom used. In 
large buildings and factories it is universally used, the use of 
steam reducing to some extent the size and cost of piping. 



530 AGRICULTURAL ENGINEERING 

QUESTIONS 

1. What are the four systems of heating farm houses now in use? 

2. Discuss the advantages and disadvantages of stoves. 

3. What are the fuels commonly used in stoves, and what are the 
advantages of each? 

4. What is considered the most satisfactory stove for cold climates? 

5. How may upper rooms be heated with the stoves below? 

6. What are the advantages of a warm-air furnace over stoves? 

7. How durable is the warm-air furnace? 

8. How much will a warm-air furnace installation cost for a six- 
room house? 

9. What arc the advantages and disadvantages of the hot-water 
syst em? 

10. Upon what does the capacity of a hot-water furnace depend? 

11. Of what materials are radiators made? 

12. Explain by a practical example how the radiating surface 
required for a house may be estimated. 

13. How will the cost of a hot-water system compare with a warm- 
air system? 

14. What are some of the objections to a steam heating system for 
farm houses? 



CHAPTER LXXXIV 
VENTILATION OF FARM BUILDINGS 

Importance of Ventilation. One of the most important 
features involved in the design of farm buildings is that of 
ventilation. It is generally recognized that men and animals 
must have fresh air, and the most favorable conditions for 
life and health are attained when the air is as pure as the open 
atmosphere. It is not practical to provide air as pure as this 
to animals housed in buildings designed primarily for shelter 
and warmth. 

The Standard of Purity. The standard of purity, or the 
extent to which pure air may be vitiated with expired air and 
still be fit to breathe, is a much-argued point. For conven- 
ience, the purity of air is designated by the number of parts 
of carbon dioxide in 10,000 parts of air. Pure air contains 
about four parts of carbon dioxide in each 10,000 parts. 

De Chaumont, an authority on ventilation, holds that six 
parts of carbon dioxide in 10,000 parts of air should be the 
standard, and other authorities recommend various and 
greater amounts. The late Professor F. H. King, of Wiscon- 
sin, recommended 16 parts as the correct standard, but em- 
phasized the great need of experiments to determine definitely 
the correct standard. There is little doubt but that if this 
lower standard were maintained generally, ventilation condi- 
tions would be much better than they are now. 

Purpose of Ventilation. The purpose of ventilation is 
threefold: (1) To supply pure air to the lungs of the animals; 
(2) to dilute and remove the products of respiration; and (3) 
to carry away the odors or the effluvium arising from the 



532 



AGRICULTURAL ENGINEERING 



excreta. The first of these is the all-important purpose; for 

no animal can live more than a few minutes without air, but 

is able to go for some time without either food or water. The 

quantity of air breathed daily by an animal greatly exceeds 

the total quantity of food and water. This is indicated by the 

following table: 

Amount of air breathed by different animals. 
{Collins Table.) 





Per hour 


Per 24 hours 




Cu. ft. 


Pounds 


Cu. ft. 


Horse 


141.7 


272 


3402 


Cow 


116.8 


224 


2804 


Pig 


46.0 


89 


1103 


Sheep 


30.2 


58 


726 


Man 


17.7 


34 


425 


Hen 


1.2 


2 


29 



To maintain the standard set by Professor King, which 

requires that the air at no time shall contain more than 3.3 

per cent of air once breathed, the following amounts of air will 

be required each hour for the various animals indicated. 

This standard may be stated as 96.7 per cent, representing 

the purity of the air, and, as before stated, it is equivalent to 

between 16 and 17 parts of carbon dioxide per 10,000 parts 

of air. 

Amount of air required per hour to maintain a standard of g6.J per 
cent. 



Horses 4296 cu. ft. per head 

Cows 3542 " " 

Swine 1392 « " 

Sheep. . 917 " " 

Hens 35 " " 

Man 537 " " 

Ventilation finally resolves itself into the problem of find- 
ing a process of dilution or mixing the air in the building with 



FARM SANITATION 



533 



fresh air fast enough to prevent the air from becoming foul 
beyond the permissible standard. The process of dilution 
may be accomplished in at least four different ways, as follows: 

1. By a process of diffusion through cloth curtains. 

2. By the action of winds. 

3. By the difference in weight of masses of air of un- 
equal temperature. 

4. By mechanical methods. 

Cloth Curtain Ventilators. Poultry houses quite gener- 
ally and dairy barns in several instances have been ventilated 
by providing thin muslin or cheesecloth curtains in place of 
the usual window glass. The theory of ventilation in this 
case holds that there is a diffusion of the foul air outward and 
the pure air inward through these 
curtains. Experiments which have 
been conducted to date, to deter- 
mine definitely the efficiency of this 
system, would indicate that it is 
unsatisfactory and unreliable. It 
is quite possible with any reason- 
able amount of curtain surface to 
provide the necessary pure air. 

Action of Winds. The action 
of the winds is one of the sim- 
plest methods of producing venti- 
lation. For instance, the wind pro- 
vides ventilation when two windows 
are opened on opposite sides of a 




321. A window ar- 
ranged so as to allow air to 
enter with the least draft. It 
may be hinged at the bottom 
building. Such an arrangement and made to close between the 



side pieces. 



would not be satisfactory on ac- 
count of the direct drafts produced, subjecting the animals 
to chills. The dangers from drafts are overcome to a large 
extent by providing suitable inlets and outlets. 



534 



AGRICULTURAL ENGINEERING 



The Sheringham valve makes a satisfactory inlet. This 
is arranged by hinging the window at the bottom and allow- 
ing it to drop inward at the top between cheeks or triangular- 
shaped side pieces. The air in striking the inclined window 
is thrown upward toward the ceiling and is not allowed to 
pass directly onto the animals which may be housed in the 
building. The fresh air is diffused through the room and the 
foul air passes out through suitable flues, not unlike those to 

be described later. Cowls 
or cupolas are used in 
connection with outlet 
flues and are designed in 
such a manner that the 
winds in blowing across 
them produce a suction 
or aspirating effect in the 
flues. 

Temperature System. 
The principle that heated 
air rises is the theory 
basis of the majority of 
the successful ventilating 
systems now in use. The 
King system, named after 
the designer, the late 
Professor F. H. King, uses 
this principle as well as 
the principle that foul 
air is heavier than pure 
air when both are at the same temperature, and tends to 
settle towards the floor. For this reason, the inlets in the 
King system discharge pure air near the ceiling and the out- 
let flues receive the air near the floor. 




Fig. 322 ; Showing one method of ar- 
ranging ttie outlet flues in the King sys- 
tem. The flues may be brought together 
to form a common outlet. 



FARM SANITATION 



535 



J 



(7 



y 



Size of Inlets and Outlets. Professor King advises four 
square feet each of outtake and intake flues for each 20 adult 
cows, for an outlet flue 20 feet high; or, in other words, 36 
square inches of cross section of flue should be provided for 
each cow. If the outlet flue be 30 feet high, 30 square inches 
of cross section will be sufficient. To be successful, there 
should be a rather large number of intakes and few out- 
takes. The outtakes should be air-tight, as straight as pos- 
sible, and as smooth as practical on the inside. One common 
^ cause of failure of this system of m 
ventilation is incorrectly con- 
structed outtakes or outlet flues. 
Often the flues are made of one 
thickness of tongued and grooved 
lumber which dries out and leaves 
open cracks which prevent the flues 
from working. Again, it is a com- 
mon occurrence to find that the 
flues are made with many sharp 
turns which restrict the flow of 
air through them. A good cupola, 
so designed as to produce a suction 
on the flues connecting into it when the wind is blowing, 
increases the efficiency of the system materially. 

Mechanical Ventilation. Mechanical ventilation is prac- 
tically unknown at the present time for farm buildings. It 
consists in providing fans or other positive means of forcing 
air into or out of a building, and is considered the only 
modern method of ventilation. The time may come when 
it will be considered in connection with farm buildings. All 
other systems depend more or less upon varying conditions of 
wind and temperature, which cannot be controlled. 



TTTTT 



1 



Fig. 323. 



Different methods 
of arranging the inlet flues in 
the King system of ventila- 
tion. 



536 AGRICULTURAL ENGINEERING 

QUESTIONS 

1. Why is the adequate ventilation of farm buildings important? 

2. Explain what is meant by "standard of purity." 

3. What are some of the standards recommended? 

4. What is the three-fold purpose of ventilation? 

5. How much air is breathed per hour by the various farm 
animals? 

6. How much air is required per hour for each of the various farm 
animals to maintain a standard of 96.7 per cent purity? 

7. In what four ways may ventilation be secured? 

8. Describe the construction and discuss the efficiency of cloth- 
curtain ventilators. 

9. How may the action of the wind be used in securing ventilation? 

10. Describe the Sheringham valve. 

11. What is the purpose of cowls or cupolas on ventilating flues? 

12. How may the heating of air be used as a basis of ventilation? 

13. Describe the construction of the King system of ventilation. 

14. What are the possibilities for mechanical ventilation? 

LIST OF REFERENCES 

Rural Hygiene, Henry N. Ogden. 

Sanitation, Water Supply, and Sewage Disposal of Country Houses, 
Wm. Paul Gerhard. 

Electric Light for the Farm, N. H. Schneider. 

Disposal of Dairy and Farm Sewage and Water Supply, Oscar Erf. 
Bulletin 143, Kansas Agricultural Experiment Station. 

Sewage Disposal Plants for Private Houses, A. Marston and F. M. 
Okey. Bulletin VI, Vol. IV., Iowa Engineering Experiment Station, 
Ames. 

Sanitation and Sewage Disposal for Country Homes, William C. 
Davidson, Bulletin No. 3, Missouri Engineering Experiment Station. 

Electric Power on the Farm, Adolph Shane. Bulletin 25, Iowa 
Engineering Experiment Station, Ames. 

Ventilation, F. H. King. 



PART NINE— ROPE WORK 

CHAPTER LXXXF 

ROPE, KNOTS, AND SPLICES 

A practical knowledge of the correct ways of tying, 
hitching, and splicing ropes is valuable to any farmer. His 
work is such that an extended use must be made of ropes; 
and such knowledge will not only be convenient and save 
time, but will also be a means of averting accidents. Only 
the more important knots, hitches, and splices will be dis- 
cussed. 

Kinds of Rope. Mention has been made in a former 
chapter concerning the various kinds of rope in use for 
transmitting power. The rope used for general purposes 
about the farm is hemp rope. As most of it is made from 
Manila hemp imported from the Philippine Islands, it is 
generally known as Manila rope. Cotton rope is some- 
times used for halters or ties. 

In making rope, the fibers are first spun into a cord or 
yarn, being twisted in a direction called "righthand." Sev- 
eral of these cords are then made into a "strand" by being 
twisted in the opposite direction, or "left-hand." The rope 
is finally made up of three or four of these strands twisted 
"righthand," and is known as a three- or a four-strand rope, 
depending upon the number of strands used. The four- 
strand rope is constructed on a core, and is heavier, more 
pliable, and stronger than the three-strand, in any given size. 

Strength of Rope. The following table gives the strength 
and weight of some of the common sizes of three-strand 
Manila rope when new and free from knots. The smallest 



538 



AGRICULTURAL ENGINEERING 



size of pulley upon which the rope should be used is also 
given. The working strength, or the greatest load the rope 
should carry with safety, is given as about one-seventh of the 
breaking load. 

Strength of different sizes of three-strand Manila rope, and size of pulley 

to use. 











Diameter of- 


Diameter 


100 lbs. rope 


Safe load 


Breaking load 


pulley 


Inches 


Pounds 


Pounds 


Pounds 


Inches 


l A 


3 


55 


400 


2 


v% 


5 


130 


900 


3 


y* 


7.6 


230 


1620 


4 


Vs 


13.3 


410 


2880 


5 


H 


16.3 


520 


3640 


6 


Vs 


23.6 


775 


5440 


7 


1 


28.3 


925 


6480 


8 



Good Knots. The three qualities of a good knot have been 
stated as follows: "(1) Rapidity with which it can be tied; 
(2) its ability to hold fast when pulled tight; and (3) the 
readiness with which it can be undone." In Kent's Mechan- 
ical Engineer's Pocket Book it is stated, "The principle 
of a good knot is that no two parts which would move in 
the same direction if the rope were to slip 
should lay along side of, and touching, each 
ther." 
Parts of the Rope. For the sake of clear- 
ness in the discussion of knots which is to 
follow, the student should understand what 
is meant by the following parts of a rope : 
The The standinq part is the long unused 

parts of a rope: a r o 

b b!-hr n c ?o a rt - P ar * °^ ^he ro P e > as represented by A, 

D, end. ' ' ° ' Fig. 324. 

The bight is the loop formed whenever the rope is turned 
back upon itself, as B. 




ROPE WORE 



539 




Square, or reef knot. 



The end is the part used in leading the rope, as D in the 
figure. 

A loop is made by crossing the sides of a bight, as C. 

KNOTS 

The square or reef knot is one of the commonest knots 

used in tying together 

ends of ropes or cords. It 

is the knot that can best 

be used in bandaging or 

in tying bundles. It does 

not slip and is quite easily untied. In tying the square 

knot, the ends are crossed, bent back on themselves, and 

crossed again, making the outside loop pass around both strands 

of the opposite end. As usually tied both ends are on one 

side instead as shown in Fig. 325. 

The Granny or False Reef Knot. If the ends of the rope 

are crossed finally in the wrong direction, the result is not 

the true square knot but 
what is known as the 
granny or false reef knot, 
as shown in Fig. 326. This 
knot, when compared with 

the true reef knot, illustrates the first principle of knots. 

It is not a good knot, and is given to explain this principle. 
The sheet bend or weaver's knot is universally used 

by weavers in tying together two ends of threads and yarns, 




Granny knot, or false reef. 




Sheet bend, or weaver's knot. 



540 



AGRICULTURAL ENGINEERING 




Bowline knot. 



and is a good knot inasmuch' as it is very secure, can be rapid- 
ly tied, and easily untied. This knot is tied by forming a 
loop with one rope end, as shown in A, Fig. 327, and then 

passing the other end back 
through this loop, as shown 
at B. When pulled tight 
the knot takes the form 
shown at C. 

The bowline knot is the 
best knot for forming a 
noose or loop 
which will not 
slip when under 
strain, and which can be easily untied. Fig. 328 
shows one method of tying the bowline. In tying 
this knot a loop is formed in the standing parts of 
the rope, as shown at the left in Fig. 328 ; then the 
end of the rope is passed through this loop around 
the rope and back through the loop, as shown at 
the right. This, perhaps, is the simplest way of 
tying this knot, but there are several other ways. s,i P knot - 

The halter, slip, or running 

knot is used where it is desired 

that the rope shall bind, as on a 

post when tying a halter rope. 

This knot is made by bending the 

end of the rope over itself and 

carrying it around the standing part 

of the rope and back through the 

loop thus formed. 

Often, in tying a halter rope, it is safer to use a bight of 

the rope through the knot and then pass the end of the rope 

through the loop so formed, as shown in Fig. 330. This 

knot unties somewhat more easily. 




329. 




330. Hitchin 



ROPE WORK 



541 




HITCHES 

The Half Hitch. The half hitch, as shown in Fig. 331, 
is not very secure, but is easily made. 

The clove hitch, as shown in Fig. 332, is 
more secure than the half hitch. It is 
often used to fasten timbers together. 

The Timber Hitch. The timber hitch, 
(Fig. 333) is used in attaching a rope -to 
timber, for hauling, and similar purposes. 
It is made by leading the end of the rope 
around the timber, then around the standing part, and back, 
making two or more turns on its own part. The strain in 

the rope will prevent the rope 
from slipping. 

The Blackwall hitch is used to 
attach a rope to a hook; and, al- 
though simple, it holds the end very 
securely. See Fig. 334. 

Two Half Hitches. Two half 
hitches may be used to good advantage, for they prevent 
the rope from slipping under any strain. They are easy to 
form, as may be learned from Fig. 335. 
The Sheepshank. The sheepshank 
is used in shortening a rope. It is 
made by gathering up the amount to 
be shortened and taking a half hitch 
around each end, as shown in Fig. 
336. If it is desired to make the 
knots more secure, the ends of the 
rope may be passed through the bights. 

FINISHING THE END OF A ROPE 

Whipping. Whipping is one of the best ways of prevent- 
ing a rope from raveling; and, as the size of the rope is not 




Clove hitch. 




Timber hitch. 



542 



AGRICULTURAL ENGINEERING 




■ig. 334. Black- 
wall hitch. 



materially increased, it can be used where the 
rope is to pass through pulleys and small 
openings. Good, stout wrapping cord should 
be used for the whipping. A loop of cord is 
laid along the end of the rope, as shown at A, 
Fig. 337. The loop is then used to wrap the 
rope, allowing the side of the loop to pass over 
the end of the rope. After the rope has been 
wrapped for a sufficient distance, the ends of 
the cord are pulled tight and then cut off, as 
shown at B. 

Crowning the end of a rope 
consists in unraveling it for a 
short distance, usually 5 or 6 
inches ; then knotting the strands 
and turning them back and weaving them 
into the rope. This increases the size of the 
rope end, but makes a very firm 
finish. The strands are first 
knotted as shown at A, Fig. 
338. Then with the aid of a 
pointed, smooth, hardwood stick 
the loose strands are woven al- 
ternately over and under the 
strands in the rope. When passed under 
three or more strands of the rope in this 
manner, the end of each loose strand may be 
cut off. To prevent kinks and to make a 
smoother finish, the loose strands may be 
slightly untwisted as they are woven into the 
rope. When finished, the crown should have 
shefpshamc the appearance of D, Fig. 338. 




ROPE WORK 



543 




"Whipping 



SPLICING 

The Short Splice. The short splice makes the rope larger 
at the splice, as a double number of strands are woven into 
the rope at one place. 
Thus in case of a 
three-strand rope the 
splice is six strands 
thick at the splice. 
This splice cannot well 
be used where the rope 
is to run over pulleys. 

To make the short splice, the ends of the rope are unlaid 
for a suitable length, which will vary from 6 to 15 inches, 
depending on the size of the rope. The strands are then 
locked together by tying by pairs strands from opposite ends 
of the rope, with a simple overhand knot, as shown at B, 
Fig. 339. After tying, the strands are woven into the rope 
in each direction by opening the rope with a hardwood pin 
and tucking them under every other strand of the rope. 
This tucking may be repeated two or more times and the 
ends then cut off, leaving a splice as shown at D. 






The Long Splice. The long splice is not so bulky as the 
short splice, and should be used where the rope is to run 



544 



AGRICULTURAL ENGINEERING 



over pulleys. It is so made that ends of the strands are 
joined at different places, making the largest number at any 
one place only one greater than the number of strands in the 




Short splice 



rope. Thus with a three-strand rope the number of strands 
through the splice is four. In making the long splice, a much 
longer length of each end of the rope is unlaid. For a ^§-inch 
rope, this should be about 18 inches; for a 3^-inch rope, 24 
inches; for a ^-inch rope, 36 inches; for an inch rope, 36 




Fig. 340. Long' splice, three-strand rope. 

inches and so on. After unlaying the rope ends for the proper 
distance, they are locked together as shown at A, Fig. 340. 
By unlaying one strand from each of the rope ends and filling 



ROPE WORK 



545 



in with one of the loose strands, bring the splice into the 
form shown at B. Then tie the strands and weave the loose 

ends into the rope as 
in the case of the 
short splice, as shown 
at C, finishing the 
splice as shown at D. 
The Side Splice. 
The end of a rope 
may be joined into 
the side of the rope 
in a similar way, as 
is shown in Fig. 341. 
Rope Halters. 
Rope halters can be 
conveniently made in a variety of forms, as shown in A, B, 
and C, in Fig. 342. The size of these halters will depend 
upon the size of the animals for which they are intended. 







Fig". 342. Rope halters. 

Their making does not require the use of any new princi- 
ples other than those discussed. 

QUESTIONS 

1. To what practical use may a knowledge of knots be put? 

2. Of what materials are ropes made? 



546 AGRICULTURAL ENGINEERING 

3. Describe the making of a rope. 

4. What size of rope should be used for a 500-pound load? 
A 1000-pound load? 

5. What are three qualities of a good knot? 

6. What is the most important principle of the knot? 

7. Name and describe the parts of a rope. 

8. Describe the following knots, and explain where they arc useful : 
The square or reef knot; the granny knot; the weaver's knot; the bow- 
line knot; the halter or slip knot. 

9. Describe the following hitches and their use: The half hitch; 
the clove hitch; the timber hitch; the Blackwall hitch; two half hitches. 

10. What is the sheepshank used for? Describe how it is made. 

11. Explain how the end of a rope may be finished by whipping. By 
crowning. 

12. Describe the making of a short splice. The long splice. The 
side splice. 

13. Describe how three styles of halters may be made. 



INDEX 



Acetylene plant, 515; cost of, 
519; generator, 517; produc- 
tion of gas, 517. 

Agricultural Engineering, de- 
fined, 13. 

Air, amount breathed by ani- 
mals, 532; amount in gas 
mixtures, 350; standard of 
purity of, 531. 

Air pressure water system, 494. 

Alfalfa, under irrigation, 119. 

Alfalfa harrow, 217. 

Ammeters, 358. 

Angle of incidence of sun's 
rays, 507. 

Angle of traces, 331. 

Areas, computing, 34; problems, 
37. 

Arrows. 21. 

Ash wood, use in tools, 196. 

Babbitting boxes, 192. 

Ball bearings, 191. 

Balloon frame, for houses, 455. 

Barns, dairy, 436; horse, 442; 
round, 449. 

Barn framing, 445. 

Basin method of irrigation, 132. 

Bathroom fixtures, 499. 

Batteries, 358. 

Beams, strength of, 406; form- 
ula for, 408. 

Bearing of a line, 53; of a 
plow, 201. 

Bearings, ball, 191; adjust- 
ment of, 193; harrow, 218; 
ring oiling, 191; roller, 191; 
self-aligning, 190. 

Beech wood, 196. 



Belting, 320; canvas, 321; 
horsepower of, 320; lacing 
of, 322; leather, 321; rubber, 
321. 

Bench marks, 43, 49. 

Bending moment, 406. 

Berm, 104. 

Bessemer steel, 197. 

Binder, grain, 244; adjustment, 
248; causes of failure to tie, 
248; engine drive, 246, 269; 
operation of, 246; selection, 
244; size, 244; tongue truck, 
246. 

Birch wood, for machines, 196. 

Blower, ensilage, 275 ; thresher, 
280. 

Boiler, steam, 376; capacity 
of, 379; .locomotive, 378; 
management of, 383; return 
flue, 379; vertical, 377. 

Boiler feeder, 382. 

Border method of irrigation. 
133. 

Boxes, of machines, 190; bab- 
bitting, 192; enclosed wheel, 
191. 

Brick, building, 410. 

Brick roads, 165. 

Bridges, concrete, 177; design 
of, 175; foundation for, 177; 
importance of, 175; size, 175. 

Bridging, 456. 

Brooks, as farm water supply, 
484. 

Bubble tube, 44. 

Buildings, farm, capital invest- 
ed in, 395; heating, 525; 
lighting, 506; location of, 
395; ventilation of, 531. 



548 



INDEX 



Cable transmission, 324. 

Calcium carbide, 515. 

Canals, 122. 

Candle, standard, 511. 

Canvas belting, 321. 

Capillary water, 57. 

Carburetors, 345, 351. 

Carriers, hay, 271. 

Cart, harrow, 213. 

Cast iron, as machine material, 
196. 

Cast steel, 197. 

Catch basin, 99. 

Cement, Portland, 410. 

Center, dead, 387. 

Cesspool, 501. 

Chaining, 23, 24. 

Check method of irrigation, 131. 

Chilled cast iron, 197. 

Clay roads, 153. 

Clutch, on tractors, 372, 392. 

Coefficient of friction, 188, 189. 

Combustion of gases, 344, 350. 

Compass, 53. 

Component forces, 314. 

Compound engines, 386. 

Compression, 352. 

Concave, 279. 

Concrete, 411; proportions for. 
412; reinforcement of, 412. 

Concrete roads, 166; bridges, 
177. 

Connecting rod, 385. 

Contour maps, 52. 

Corn harvesters, 251; binders, 
252; huskers, 256; pickers, 
254; shocker, 254; shredder. 
256; sled cutters, 251. 

Corn planters, 231; adjust- 
ment, 236; conveniences, 
235 ; dropping mechanisim 
226; essentials of, 231; fur- 
row-openers, 234; graded 
seed for, 238; wheels, 234; 
variable drop, 233. 

Correction lines, 39. 

Cow ties, 440. 

'Crank shaft, 385. 



Crowning a rope, 542. 

Crown sheet, 378. 

Cultivators, 237; construction, 
238; balance frame, 240; 
disk, 242; guiding devices, 
241; seats, 241; selection 
of, 237; surface, 242; walk- 
ing, 238; wheels, 240. 

Culverts, 175; concrete, 178; 
design of, 175; importance 
of, 175; pipe, 178; size, 175. 

Cutters, ensilage, 273; con- 
struction, 276; elevating me- 
chanism, 275; mounting, 275; 
selection of, 276; self-feed, 
275; types, 273. 

Cylinder, 488; threshing, 278. . 

Dairy barns, 436; construction 
details, 437; essentials of, 
436; types, 436. 

Datum, 42. 

Dead center, 387. 

Declination of the needle, 53. 

Deep-tilling machine, 206. 

Deere, John, 181. 

Differential, 393. 

Disk harrow, 213. 

Disk plow, 204. 

Ditches, cost of digging, 101; 
digging for tile, 86, 93; fill- 
ing, 96; grading, 89; open, 
103. 

Ditching machines, 87. 

Draft, of plows, 204; principles 
of, 330. 

Drainage, 56; benefits of, 61; 
districts, 108; history of, 56; 
land drainage, 86; lands 
needing, 58; open ditch, 103; 
systems of, 67; underdrain- 
age, 59. 

Drainage districts, 108; assess- 
ments, 109; defined, 108; 
laws for, 108 ; survey of, 109. 

Drainage engineer, 64. 

Drainage system, 67. 

Drainage wells, 100. 



INDEX 



549 



Drawing instruments, 28. 

Drills, 225; adjustment of, 229; 
force feeds, 227; furrow- 
openers, 225; horse lift, 229; 
press drill, 228; seed tubes, 
228; selection of, 228. 

Dynamometers, 317. 

Dynamos, 358. 

Earth, roads, 147; construction, 
147; crown, 149; drainage 
of, 147; extent, 147; grades, 
151; maintenance, 150. 

Efficiency of lamps, 513; of a 
machine, 186. 

Elasticity, denned, 404. 

Electric light, 520; cost of, 
524; plant, 521; selection of 
plant, 522; source of power, 
521. 

Electrical terms, 522. 

Elements of machines, 186. 

Elevation of a point, 42. 

Elevators, ensilage, 275; por- 
table farm, 287. 

Energy, kinds denned, 313. 

Engineer, drainage, 64. 

Engineering, defined, 13. 

Engine gang plows, 208. 

Engines, gasoline or oil, 344; 
measuring power of, 316: 
operation of, 350; steam. 
376, 385; tractors, 370, 389. 

Ensilage machinery, 273. 

Equilibrium, defined, 402. 

Essentials of a machine, 187. 

Eveners, 334; four-, five-, and 
six-horse, 336; placement of 
holes, 334; plain, 337; three- 
horse, 335. 

Factor of safety, 405. 

Fanning mills, 282. 

Farmhouse, the, 451; con- 
structing, 455; features of 
construction, 451 ; location 
of, 451; plan of, 452. 

Farm machinery, 180. 



Farm mechanics, defined, 15. 

Farm sanitation, 480. 

Farm structures, 395. 

Feed mills, 298. 

Feed water heater, 382. 

Fields, leveling, 52. 

Fixtures, bathroom, 499 ; 

plumbing, 497. 
Flagstaff, 21. 
Flooding method of irrigation, 

131. 
Flow of water, in ditches, 105; 

in pipes, 491; in tile, 78. 
Foaming in boilers, 383. 
Foot pound, defined, 314. 
Force, action of, 402; defined, 

314. 
Forks, hay, 270. 
Friction, coefficient of, 188, 189; 

defined, 187; of rest, 188; 

rolling, 188. 
Friction gearing, 325. 
Fuels, for engines, 344. 
Full frame, 445, 455. 
Furnaces, for boilers, 377; for 

houses, 526. 
Furrow method of irrigation, 

133. 
Fusible plug, 382. 

Gang plows, 201; engine, 208. 

Gas mixture for engines, 350; 
testing, 352. 

Gasoline engines, 344; classes, 
344; estimating horsepower 
of, 367; four-stroke cycle, 
346; fuel for, 344; operation 
of, 350; for pumping, 486; 
selection of, 361; testing, 
366; two-stroke cycle, 347; 
types, 345; use on binders, 
246, 364. 

Gasoline lamps, 514. 

Gas tractors, 370. 

Gauge, cocks, 380; glass, 381; 
pressure, 381. 

Gearing, for transmitting pow- 
er, 324; traction, 373, 393. 



550 



INDEX 



Governor, engine, 387. 
Graders, grain, 282. 
Grading tile drains, 73, 89. 
Grain, under irrigation, 118. 
Graphite, as a lubricant, 189. 
Gravel roads, 154; binder, 155; 

cost of, 158; drainage of, 

156: maintenance of, 158; 

surface construction, 156. 
Grease cups, 192. 
Grip, of horse, influence on 

draft, 331. 
Gunter's chain, 18. 
Gunter's chain measure, 19. 

Halters, rope, 545. 

Harrow attachment for plows, 
219. 

Harrows, 211; cart for, 213; 
construction of, 212, 215; 
disk, 213; smoothing, 211; 
spring-tooth, 213. 

Harvester, corn, 251; grain, 
244. 

Hav machinery, barn, 270; 
field, 258. 

Heating systems, 525; fur- 
naces, 526; stoves, 525. 

Hickory wood, qualities and 
uses, 196. 

Hillside plow, 207. 

Hitch, length of, influence on 
draft, 332. 

Hitches, 541. 

Hog houses, 414; individual, 
417; large, 419. 

Horse, amount of service from, 
329; as a motor, 327; capa- 
city of, 328; draft, 330; size 
of teams, 329; weight, etc. 
of, influence on draft, 330. 

Horse barns, features of con- 
struction, 442. 

Horsepower, 314; estimating, 
engines, 316, 366. 

Hot water heating system, 52S.- 

Husker, corn, 256. 



Hussey, Obed, 181. 
Hydrostatic water, 57. 

Ignition, in oil engines, 354; 
jump-spark system, 357; 
make-and-break system, 355. 

Implement, defined, 186. 

Implement house, 473; details 
of construction, 474; loca- 
tion, 473; size, 473. 

Incandescent lamp, 521. 

Injector, 382. 

Instruments, for leveling, 42; 
for measuring, 18. 

Iowa silo, 469. 

Iron, cast, 196; wrought, 197. 

Irrigation, 111; amount of wa- 
ter used in, 117; applying 
water in, 129; crops grown 
by, 118; history of, 112; pre- 
paring land for, 130; pur- 
poses of, 113; sewage dis- 
posal by, 138; supplying 
water for, 122. 

Irrigation culture, 115; in 
humid regions, 136. 

Jacks, lifting, 287. 
Journal, 190. 
Jump-spark ignitors, 357. 

Kerosene lamps, 511. 

Knots, essentials of a good, 

538; kinds, 539. 
Knotter, binder, 248. 
Kutter's formula, 105. 

Labor, farm, influence of ma- 
chinery on, 181; of inconven- 
ient buildings on, 395. 

Lakes, as farm water supply, 
484. 

Lamps, efficiency of, 513; gas- 
oline, 514; kerosene, 511. 

Land rollers, 220. 

Laundry, in farmhouse, 454. 

Laying out the farm, 396. 

Leaks, in oil engines, 353. 



INDEX 



551 



Leather belting, 321. 
Lettering, 32. 

Level, 45; adjustments of, 46. 
Leveling, definition of terms, 

42; practice, 49; tile drains, 

73. 
Light, unit of, 511. 
Lighting systems for buildings, 

acetylene, 515; development, 

510; lamps, 511; natural, 

506; electric, 520. 
Lime, for motar, 410. 
Linear measure, 19. 
Liners, 193. 
Link belting, 323. 
Loaders, hay, 266. 
Locomotive boiler, 378, 528. 
Lubrication, 189; choice of 

lubricant, 189. 



McCormick, Cyrus W., 181. 
Macadam roads, 160; bitumi- 
nous, 163. 

Machine, defined, 186; ele- 
ments of, 186. 

Machine shed, 473. 

Machinery, farm, 180; binder, 
239; care of, 309; corn 
harvester, 252 ; corn shellers, 
299; definitions and princi- 
ples, 186; elevators, 287; 
ensilage, 273; fanning mills, 
282; feed mills, 298; hay, 
258; influence of, 181; in- 
troduction of, 180; manure 
spreaders, 292; motors, 313: 
threshing, 278 ; spraying, 
303; windmills, 339. 

Magnetos, 358. 

Manure spreaders, 292. 

Malleable iron, for machines, 
197. 

Maps, contour, 52; final, 70; 
preliminary survey, 66. 

Map making, 28. 

Maple wood, qualities of, 196. 



Markets, influenced by roads, 

143. 
Materials, mechanics of, 402, 

406; used in machinery, 195. 
Measurement of power, 316; 

of water, 134. 
Measuring, 18; instruments 

for, 20; tables for, 19. 
Mechanics, defined, 15. 
Mechanics of materials, 402, 

406. 
Meridian, guide, 39; principal, 

38. 
Metes and bounds, surveys by, 

40. 
Modulus of rupture, 408. 
Modulus of section, 407. 
Moment of a force, 402. 
Monuments, 40. 
Motors, classification of, 344; 

farm, 313; horses as, 327. 
Mowers, 258; adjustment, 262; 

construction, 258; size, 258; 

types, 258. 

Newbold, Chas., 180. 
Notes, field, 24, 50. 

Oak, as material for machines, 

196. 
Oil cups, 192. 
Open ditches, 103; capacity of, 

104; construction of, 103; 

cost of, 104; disadvantages 

of, 104. 
Orchard irrigation, 121. 

Pacing, 23. 

Perry pneumatic water supply 
system, 495. 

Pine, for machines, 196. 

Pipes, water, 491; flow of wa- 
ter in, 492; sizes, 491; sys- 
tems, 492. 

Plank frame for barns, 445. 

Planter, corn, 231. 

Plastering, 458. 



552 



INDEX 



Plows, 199; adjustment, 200; 
construction, 200; disk, 204; 
draft of, 204; engine gang, 
208; gang, 201; harrow at- 
tachment for, 219; hillside, 
207; selection of, 199; size, 
199; sulky, 201; types of, 
199. 

Plumb line, 43. 

Plumbing, for houses, 497; fix- 
tures, 497. 

Plungers, for pumps, 489. 

Poncelet's formula, 79. 

Population on farms, 183. 

Poplar wood, qualities and 
uses, 196. 

Potatoes under irrigation, 120. 

Poultry houses, 425 ; construc- 
tion details, 426'; location, 
425; size, 425; types, 432. 

Power, defined, 314; for light- 
ing plant, 521; for pumping, 
486; from horses, 327; meas- 
urement of, 316; required 
for machinery, 361; trans- 
mission of, 320. 

Power mills, 298, 340. 

Preliminary survey, 64. 

Pressure gauge, 381. 

Prime movers, 313. 

Profile, leveling, 49; grade, 74. 

Prony break, 316. 

Pumps, 487; important fea- 
tures of, 488. 

Pumping plant, 486. 

Pumpinng water, cost of with 
engine, 363; for irrigation, 
125. 

Pulleys, 322; calculating speed 
of, 323. 

Purlines, 445. 

Pulverizers, 221. 

Quadrants, for transmitting 
power, 324. 

Radiation, estimating, 529. 
Radiators, 526, 529. 



Rakes, sweep, 268; sulky, 259; 

side delivery, 260. 
Range of townships, 39. 
Range pole, 21. 
Rating, of tractors, 392. 
Rectangle, area of, 34. 
Reinforcement of concrete, 

412. 
Repair of machinery, 309. 
Reservoirs, for irrigation, 123; 

home water supply, 493. 
Resultant, defined, 314. 
Resurveys, 40. 
Reversible plow, 207. 
Road drag, 150, 173. 
Road grader, 97; elevating, 

169; scraping, 168. 
Road machinery, 167; classes, 

167; scrapers, 167. 
Roads, 141; benefits of good, 

142; brick, 165; clay, 153; 

earth, 147; extent of, 141; 

gravel, 154; history of, 14; 

requisites of good, 145; 

sand, 153; sand-clay, 153; 

scrapers for, 167; stone, 160. 
Road rollers, 170. 
Road stone, 160; testing, 161. 
Rock crushers, 172. 
Roller bearings, 191. 
Rollers, for roads, horse, 170; 

land, 220; power, 171; tan- 
dem, 171. 
Rope transmission, 323. 
Round barns, 449. 
Rubber belting, 321. 
Run-off, computing, 80. 



Safety valve, 381. 

Sand, for building, 411. 

Sand-clay roads, 153. 

Sand roads, 153. 

Sanitation, 480. 

Scrapers, for disk harrows, 218: 

road, 167. 
Sections of townships, 39. 



INDEX 



553 



Seeders, end gate, 224; hand, 
223; seed-box broadcast, 224; 
utility of, 223; wheelbarrow, 
224. 

Self-aligning bearing, 190. 

Septic tank, 501; construction 
of, 504. 

Sewage disposal, principles of, 
502; by irrigation, 114, 138; 
systems of, 501. 

Shafting, 325. 

Shawver barn frame, 446, 448. 

Sherringham valve, 534. 

Shredders, 256. 

Shop, farm., 477. 

Side draft, overcoming, 337. 

Silos, 461; essentials, 463; lo- 
cation, 461; masonry, 468; 
size, 461; wood, 465. 

Silt basins, 99. 

Sled corn cutters, 251. 

Slings, hay, 271. 

Soils, improved by drainage, 
61; kinds of, 59. 

Splices, 543. 

Spraying machinery, 303. 

Spraying method of irrigation, 
134. 

Springs, as water supply, 483. 

Spring-tooth harrow, 213. 

Stackers, hay, 269; straw, 280. 

Stalls, cow, 440; horse, 443. 

Standard of purity of air, 531. 

State Highway Commission, 
178. 

Statics defined, 402. 

Steam boiler, 376; accessories, 
380; capacity of, 379; func- 
tions of, 377; management, 
388; principle of, 376; types, 
377. 

Steam engines, 376, 385; kinds. 
386; principle of, 385. 

Steam, formation, 377; quality 
of, 380. 

Steel, Bessemer, 197; cast, 197; 
mild, 197; soft center, 198; 
tool, 198. 



Stone, building, 409. 

Stone roads, 160; construction 
of, 162; cost of, 165; main- 
tenance of, 165. 

Stoves, 525. 

Strength of materials, 402, 406. 

Stress, defined, 403; kinds of, 
403. 

Subirrigation, 133. 

Subsurface packer, 220. 

Suction of plows, 200. 

Sugar beets under irrigation, 
120. 

Sulky plows, 201; adjustments 
of, 203. 

Sunlight as a sanitary agent, 
506. 

Surface measure, 19. 

Survey, defined, 16; prelimi- 
nary, 64. 

Surveying, agricultural, 16; 
divisions of, 17; problems, 26. 

Surveyor's measure, 20; uses 
of, 16. 

Sweep rakes, 268. 

Tanks, water, 493. 

Tapes, 20; care and use of, 22. 

Teams, size of, 329. 

Tedder, hay, 267. 

Telford roads, 160. 

Temperature system of ventila- 
tion, 534. 

Tests, of concrete, 411; engines, 
316, 36"6; horse, 328. 

Threshing machinery, 278. 

Tile, blinding, 94; cement, 92; 
inspection of, 94; laying, 92; 
roots of trees in, 100; select- 
ing, 91. 

Tile drains, capacity of, 78; 
cause of flow in, 78; construc- 
tion of, 96; cost of, 101; 
depth, 67; digging ditches, 
86; distance apart, 68; filling, 
96; outlet of, 98; size of lat- 
erals, 84 ; staking out, 71 ; 
systems of, 69. 



554 • 



INDEX 



Tongue truck, 338; for harrows, 
218. 

Tool, denned, 186. 

Tool shop, 477. 

Topographical signs, 31. 

Towers, water, 493; windmill, 
342. 

Township, division and num- 
bering, 38; sections of, 39. 

Traces, proper angle of, 331. 

Tracks, hay, 272. 

Tractor, steam, 389. 

Transit, 54. 

Transmission of power, 320. 

Transportation, cost of, 142. 

Transport truck, 219. 

Trapezium, area of, 35. 

Trapezoid, area of, 35. 

Ti-iangles, area of, 34; trans- 
mission of power by, 324. 

Trucks, transport, 219. 

Turning point, 52. 

Ultimate strength of materials. 

404. 
Underdrainage, 59. 
United States system of land 

survey, 38. 

Valve action in oil engines, 359. 
Valves, for pumps, 489; safety, 

381. 
Ventilation of farm buildings, 

531; influence of wind, 533; 

mechanical, 535; purposes of, 

31; temperature system, 534. 
Ventilator, cloth curtain, 533. 
Vertical boiler, 377. 



Wages, influence of farm ma- 
chinery on, 182. 

Warm-air furnace, 526. 

Waste bank, 104. 

Water, capillary, 57; control of, 
111; duty of, 56; hydrostatic, 
57; measurement of, 134; reg- 
ulation of soil water, 56; re- 
quired for crops, 115; used in 
irrigation, 117. 

Water level, 43; laying tile by, 
89. 

Water pipe, 491; flow of water 
in, 491; sizes, 491; systems, 
492. 

Water supply, 480. 

Water wheels, 487. 

Weigher, 280. 

Weir, 134. 

Wells, 480. 

Whipping a rope, 541. 

Windmills, 339; construction, 
341; development, 339; power 
of, 341; regulation, 341; size 
of, 340; towers, 342; types of, 
340; utility of, 339, 486. 

Windows, design of, 5'08; loca- 
tion of, 507; size of, 508. 

Wing joist barn frame, 446. 

Wire rope transmission, 324. 

Wood, as a material for ma- 
chines, 195. 
Work, defined, 186, 314. 
Working stress, defined, 404. 
Wrought iron, 197. 
Wye level, 46. 



Agricultural Text Books 

FOR 

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This series of agricultural books, of which Agricultural Engineering 
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FIELD CROPS 



By A. D. WILSON, Sup't of Farmers' Institutes and Exten- 
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where they can profitably spend stormy days. Illustrated, 100 pp. 
Price, 12 mo., cloth, 50 cents. 

STANDARD BLACKSMITHING, HORSESHOEING AND 
WAGON MAKING, by J. G. Holmstrom, author of "Modern Black- 
smithing, " gives practical instructions by a successful blacksmith. The 
latest and most complete book on the subject published. Thoroughly 
illustrated. Price, 12 mo., cloth, $1.00. 

GRASSES AND HOW TO GROW THEM, by Thomas Shaw. 
Discusses the economic grasses fo the United States and Canada from 
the standpoint of the farmer and the stockmen. Price, 450 pages, cloth, 
$1.50 postpaid. 



WEBB PUBLISHING CO. . ST. PAUL, MINN. 




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LIBRARY OF CONGRESS 



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